Adding flang as a fortran compiler

[curtywang]

• [X] I read the conda-forge documentation and could not find the solution for my problem there.

Issue: flang is available as a compiler for fortran on Windows (flang_win-64 feedstock), but is not currently added as part of the options here in the compilers feedstock, so packages that require a fortran compiler on Windows get stuck on requesting vc14 and flang 5.0 for some reason:

Encountered problems while solving:
  - nothing provides vc 14 needed by flang-5.0.0-vc14_1

Environment (conda list):

``` $ mamba list # Name Version Build Channel anyio 3.4.0 py39hcbf5309_0 conda-forge argon2-cffi 21.1.0 py39hb82d6ee_2 conda-forge arviz 0.11.4 pyhd8ed1ab_0 conda-forge astroid 2.9.0 py39hcbf5309_0 conda-forge async_generator 1.10 py_0 conda-forge attrs 21.2.0 pyhd8ed1ab_0 conda-forge autopep8 1.6.0 pyhd8ed1ab_1 conda-forge babel 2.9.1 pyh44b312d_0 conda-forge backcall 0.2.0 pyh9f0ad1d_0 conda-forge backports 1.0 py_2 conda-forge backports.functools_lru_cache 1.6.4 pyhd8ed1ab_0 conda-forge bambi 0.6.3 pypi_0 pypi blas 2.112 mkl conda-forge blas-devel 3.9.0 12_win64_mkl conda-forge bleach 4.1.0 pyhd8ed1ab_0 conda-forge boost-cpp 1.77.0 h5b4e17d_1 conda-forge brotli 1.0.9 h8ffe710_6 conda-forge brotli-bin 1.0.9 h8ffe710_6 conda-forge brotlipy 0.7.0 py39hb82d6ee_1003 conda-forge bzip2 1.0.8 h8ffe710_4 conda-forge ca-certificates 2021.10.8 h5b45459_0 conda-forge cachetools 4.2.4 pyhd8ed1ab_0 conda-forge cairo 1.16.0 hb19e0ff_1008 conda-forge certifi 2021.10.8 py39hcbf5309_1 conda-forge cffi 1.15.0 py39h0878f49_0 conda-forge cftime 1.5.1.1 py39h5d4886f_1 conda-forge chardet 4.0.0 py39hcbf5309_2 conda-forge charset-normalizer 2.0.8 pyhd8ed1ab_0 conda-forge clang 11.0.1 h57928b3_1 conda-forge clang-11 11.0.1 default_h5c34c98_1 conda-forge clang-tools 11.0.1 default_h5c34c98_1 conda-forge clangdev 11.0.1 default_h5c34c98_1 conda-forge clangxx 11.0.1 default_h5c34c98_1 conda-forge colorama 0.4.4 pyh9f0ad1d_0 conda-forge conda 4.11.0 py39hcbf5309_0 conda-forge conda-package-handling 1.7.3 py39hb3671d1_1 conda-forge cppad 20210000.8 h0e60522_0 conda-forge cryptography 36.0.0 py39h7bc7c5c_0 conda-forge curl 7.80.0 h789b8ee_0 conda-forge cvxopt 1.2.7 py39h73f7814_1 conda-forge cvxpy 1.1.17 py39hcbf5309_1 conda-forge cvxpy-base 1.1.17 py39h2e25243_1 conda-forge cycler 0.11.0 pyhd8ed1ab_0 conda-forge debugpy 1.5.1 py39h415ef7b_0 conda-forge decorator 5.1.0 pyhd8ed1ab_0 conda-forge defusedxml 0.7.1 pyhd8ed1ab_0 conda-forge dill 0.3.4 pyhd8ed1ab_0 conda-forge dsdp 5.8 h6e01ec9_1203 conda-forge ecos 2.0.8 py39h5d4886f_2 conda-forge entrypoints 0.3 py39hde42818_1002 conda-forge expat 2.4.1 h39d44d4_0 conda-forge fastprogress 1.0.0 py_0 conda-forge fftw 3.3.10 nompi_hb424310_101 conda-forge filelock 3.4.0 pyhd8ed1ab_0 conda-forge flake8 4.0.1 pyhd8ed1ab_0 conda-forge flang 11.0.1 h0e60522_20210131 conda-forge flang_win-64 11.0.1 h57928b3_20210131 conda-forge font-ttf-dejavu-sans-mono 2.37 hab24e00_0 conda-forge font-ttf-inconsolata 3.000 h77eed37_0 conda-forge font-ttf-source-code-pro 2.038 h77eed37_0 conda-forge font-ttf-ubuntu 0.83 hab24e00_0 conda-forge fontconfig 2.13.1 h1989441_1005 conda-forge fonts-conda-ecosystem 1 0 conda-forge fonts-conda-forge 1 0 conda-forge fonttools 4.28.2 py39hb82d6ee_0 conda-forge formulae 0.2.0 pypi_0 pypi freetype 2.10.4 h546665d_1 conda-forge fribidi 1.0.10 h8d14728_0 conda-forge getopt-win32 0.1 h8ffe710_0 conda-forge gettext 0.19.8.1 ha2e2712_1008 conda-forge glpk 4.65 h8ffe710_1004 conda-forge graphite2 1.3.13 1000 conda-forge graphviz 2.49.3 hefbd956_0 conda-forge gsl 2.7 hdfb1a43_0 conda-forge gts 0.7.6 h7c369d9_2 conda-forge harfbuzz 3.1.1 hc601d6f_0 conda-forge hdf4 4.2.15 h0e5069d_3 conda-forge hdf5 1.12.1 nompi_h2a0e4a3_102 conda-forge icu 68.2 h0e60522_0 conda-forge idna 3.1 pyhd3deb0d_0 conda-forge importlib-metadata 4.8.2 py39hcbf5309_0 conda-forge importlib_metadata 4.8.2 hd8ed1ab_0 conda-forge importlib_resources 5.4.0 pyhd8ed1ab_0 conda-forge intel-openmp 2021.4.0 h57928b3_3556 conda-forge ipopt 3.11.1 2 conda-forge ipykernel 6.5.1 py39h832f523_0 conda-forge ipython 7.30.0 py39hcbf5309_0 conda-forge ipython_genutils 0.2.0 py_1 conda-forge isort 5.10.1 pyhd8ed1ab_0 conda-forge jbig 2.1 h8d14728_2003 conda-forge jedi 0.18.1 py39hcbf5309_0 conda-forge jinja2 3.0.3 pyhd8ed1ab_0 conda-forge joblib 1.1.0 pyhd8ed1ab_0 conda-forge jpeg 9d h8ffe710_0 conda-forge json5 0.9.5 pyh9f0ad1d_0 conda-forge jsonschema 4.2.1 pyhd8ed1ab_0 conda-forge jupyter-lsp 1.5.0 pyhd8ed1ab_0 conda-forge jupyter_client 7.1.0 pyhd8ed1ab_0 conda-forge jupyter_core 4.9.1 py39hcbf5309_1 conda-forge jupyter_server 1.12.1 pyhd8ed1ab_0 conda-forge jupyterlab 3.2.4 pyhd8ed1ab_0 conda-forge jupyterlab-drawio 0.9.0 pyhd8ed1ab_0 conda-forge jupyterlab-lsp 3.9.1 pyhd8ed1ab_0 conda-forge jupyterlab-mathjax3 4.2.2 pyhd8ed1ab_0 conda-forge jupyterlab-spellchecker 0.7.2 pyhd8ed1ab_0 conda-forge jupyterlab-variableinspector 3.0.9 pyhd8ed1ab_0 conda-forge jupyterlab_pygments 0.1.2 pyh9f0ad1d_0 conda-forge jupyterlab_server 2.8.2 pyhd8ed1ab_0 conda-forge kiwisolver 1.3.2 py39h2e07f2f_1 conda-forge krb5 1.19.2 h20d022d_3 conda-forge lapack 3.9.0 netlib conda-forge lazy-object-proxy 1.6.0 py39hb82d6ee_1 conda-forge lcms2 2.12 h2a16943_0 conda-forge lerc 3.0 h0e60522_0 conda-forge libarchive 3.5.2 hb45042f_1 conda-forge libblas 3.9.0 12_win64_mkl conda-forge libbrotlicommon 1.0.9 h8ffe710_6 conda-forge libbrotlidec 1.0.9 h8ffe710_6 conda-forge libbrotlienc 1.0.9 h8ffe710_6 conda-forge libcblas 3.9.0 12_win64_mkl conda-forge libclang 11.0.1 default_h5c34c98_1 conda-forge libclang-cpp 11.0.1 default_h5c34c98_1 conda-forge libcurl 7.80.0 h789b8ee_0 conda-forge libcxx 7.0.0 h1ad3211_1002 conda-forge libdeflate 1.8 h8ffe710_0 conda-forge libffi 3.4.2 h8ffe710_5 conda-forge libflang 11.0.1 h0e60522_20210131 conda-forge libgd 2.3.3 h8bb91b0_0 conda-forge libglib 2.70.1 h3be07f2_0 conda-forge libgpuarray 0.7.6 h8ffe710_1003 conda-forge libiconv 1.16 he774522_0 conda-forge liblapack 3.9.0 12_win64_mkl conda-forge liblapacke 3.9.0 12_win64_mkl conda-forge libllvm11 11.0.1 hab3b255_0 conda-forge libmamba 0.19.0 h44daa3b_0 conda-forge libmambapy 0.19.0 py39h9c8ecf5_0 conda-forge libnetcdf 4.8.1 nompi_h1cc8e9d_101 conda-forge libpng 1.6.37 h1d00b33_2 conda-forge libpython 2.1 py39hcbf5309_1 conda-forge libsodium 1.0.18 h8d14728_1 conda-forge libsolv 0.7.19 h7755175_5 conda-forge libssh2 1.10.0 h680486a_2 conda-forge libtiff 4.3.0 hd413186_2 conda-forge libwebp 1.2.1 h57928b3_0 conda-forge libwebp-base 1.2.1 h8ffe710_0 conda-forge libxcb 1.13 hcd874cb_1004 conda-forge libxml2 2.9.12 hf5bbc77_1 conda-forge libzip 1.8.0 hfed4ece_1 conda-forge libzlib 1.2.11 h8ffe710_1013 conda-forge llvm-meta 7.0.0 0 conda-forge llvm-openmp 11.0.1 h2d74725_0 conda-forge llvm-tools 11.0.1 hab3b255_0 conda-forge llvmdev 11.0.1 hab3b255_0 conda-forge llvmlite 0.37.0 py39ha0cd8c8_1 conda-forge lz4-c 1.9.3 h8ffe710_1 conda-forge lzo 2.10 he774522_1000 conda-forge m2w64-gcc-libgfortran 5.3.0 6 conda-forge m2w64-gcc-libs 5.3.0 7 conda-forge m2w64-gcc-libs-core 5.3.0 7 conda-forge m2w64-gmp 6.1.0 2 conda-forge m2w64-libwinpthread-git 5.0.0.4634.697f757 2 conda-forge mako 1.1.6 pyhd8ed1ab_0 conda-forge mamba 0.19.0 py39hb3d9227_0 conda-forge markupsafe 2.0.1 py39hb82d6ee_1 conda-forge matplotlib 3.5.0 py39hcbf5309_0 conda-forge matplotlib-base 3.5.0 py39h581301d_0 conda-forge matplotlib-inline 0.1.3 pyhd8ed1ab_0 conda-forge mccabe 0.6.1 py_1 conda-forge menuinst 1.4.18 py39hcbf5309_1 conda-forge miniforge_console_shortcut 2.0 h57928b3_1 conda-forge mistune 0.8.4 py39hb82d6ee_1005 conda-forge mkl 2021.4.0 h0e2418a_729 conda-forge mkl-devel 2021.4.0 h57928b3_730 conda-forge mkl-include 2021.4.0 h0e2418a_729 conda-forge mkl-service 2.4.0 py39h6b0492b_0 conda-forge msys2-conda-epoch 20160418 1 conda-forge munkres 1.1.4 pyh9f0ad1d_0 conda-forge nbclassic 0.3.4 pyhd8ed1ab_0 conda-forge nbclient 0.5.9 pyhd8ed1ab_0 conda-forge nbconvert 6.3.0 py39hcbf5309_1 conda-forge nbformat 5.1.3 pyhd8ed1ab_0 conda-forge nest-asyncio 1.5.1 pyhd8ed1ab_0 conda-forge netcdf4 1.5.8 nompi_py39hf113b1f_101 conda-forge notebook 6.4.6 pyha770c72_0 conda-forge numba 0.54.1 py39hb8cd55e_0 conda-forge numpy 1.20.3 py39h6635163_1 conda-forge olefile 0.46 pyh9f0ad1d_1 conda-forge openjpeg 2.4.0 hb211442_1 conda-forge openssl 1.1.1l h8ffe710_0 conda-forge osqp 0.6.2.post0 py39h2e25243_3 conda-forge packaging 21.3 pyhd8ed1ab_0 conda-forge pandas 1.3.4 py39h2e25243_1 conda-forge pandoc 2.16.2 h8ffe710_0 conda-forge pandocfilters 1.5.0 pyhd8ed1ab_0 conda-forge pango 1.48.10 h33e4779_2 conda-forge parso 0.8.3 pyhd8ed1ab_0 conda-forge patsy 0.5.2 pyhd8ed1ab_0 conda-forge pcre 8.45 h0e60522_0 conda-forge pickleshare 0.7.5 py39hde42818_1002 conda-forge pillow 8.4.0 py39h916092e_0 conda-forge pip 21.3.1 pyhd8ed1ab_0 conda-forge pixman 0.40.0 h8ffe710_0 conda-forge platformdirs 2.3.0 pyhd8ed1ab_0 conda-forge pluggy 1.0.0 py39hcbf5309_2 conda-forge prometheus_client 0.12.0 pyhd8ed1ab_0 conda-forge prompt-toolkit 3.0.22 pyha770c72_0 conda-forge pthread-stubs 0.4 hcd874cb_1001 conda-forge pybind11-abi 4 hd8ed1ab_3 conda-forge pycodestyle 2.8.0 pyhd8ed1ab_0 conda-forge pycosat 0.6.3 py39hb82d6ee_1009 conda-forge pycparser 2.21 pyhd8ed1ab_0 conda-forge pydocstyle 6.1.1 pyhd8ed1ab_0 conda-forge pyflakes 2.4.0 pyhd8ed1ab_0 conda-forge pygments 2.10.0 pyhd8ed1ab_0 conda-forge pygpu 0.7.6 py39h5d4886f_1003 conda-forge pylint 2.12.1 pyhd8ed1ab_0 conda-forge pymc3 3.11.4 pypi_0 pypi pyopenssl 21.0.0 pyhd8ed1ab_0 conda-forge pyparsing 3.0.6 pyhd8ed1ab_0 conda-forge pyqt 5.12.3 py39hcbf5309_8 conda-forge pyqt-impl 5.12.3 py39h415ef7b_8 conda-forge pyqt5-sip 4.19.18 py39h415ef7b_8 conda-forge pyqtchart 5.12 py39h415ef7b_8 conda-forge pyqtwebengine 5.12.1 py39h415ef7b_8 conda-forge pyrsistent 0.18.0 py39hb82d6ee_0 conda-forge pyscipopt 3.4.0 pypi_0 pypi pysocks 1.7.1 py39hcbf5309_4 conda-forge python 3.9.7 h7840368_3_cpython conda-forge python-dateutil 2.8.2 pyhd8ed1ab_0 conda-forge python-graphviz 0.19 pyhaef67bd_0 conda-forge python-lsp-jsonrpc 1.0.0 pyhd8ed1ab_0 conda-forge python-lsp-server 1.3.2 pyhd8ed1ab_0 conda-forge python_abi 3.9 2_cp39 conda-forge pytz 2021.3 pyhd8ed1ab_0 conda-forge pywin32 302 py39hb82d6ee_2 conda-forge pywinpty 1.1.6 py39h99910a6_0 conda-forge pyzmq 22.3.0 py39he46f08e_1 conda-forge qdldl-python 0.1.5 py39h2e25243_2 conda-forge qt 5.12.9 h5909a2a_4 conda-forge reproc 14.2.3 h8ffe710_0 conda-forge reproc-cpp 14.2.3 h0e60522_0 conda-forge requests 2.26.0 pyhd8ed1ab_1 conda-forge requests-unixsocket 0.2.0 py_0 conda-forge rope 0.22.0 pyhd8ed1ab_0 conda-forge ruamel_yaml 0.15.80 py39hb82d6ee_1006 conda-forge scikit-learn 1.0.1 py39he931e04_2 conda-forge scipy 1.7.3 py39hc0c34ad_0 conda-forge scs 3.0.0 py39hc73de48_1 conda-forge seaborn 0.11.2 hd8ed1ab_0 conda-forge seaborn-base 0.11.2 pyhd8ed1ab_0 conda-forge semver 2.13.0 pyh9f0ad1d_0 conda-forge send2trash 1.8.0 pyhd8ed1ab_0 conda-forge setuptools 59.4.0 py39hcbf5309_0 conda-forge simpy 4.0.1 pyhd8ed1ab_0 conda-forge six 1.16.0 pyh6c4a22f_0 conda-forge sniffio 1.2.0 py39hcbf5309_2 conda-forge snowballstemmer 2.2.0 pyhd8ed1ab_0 conda-forge sqlite 3.37.0 h8ffe710_0 conda-forge statsmodels 0.13.1 py39h5d4886f_0 conda-forge tbb 2021.4.0 h2d74725_1 conda-forge tbb-devel 2021.4.0 h2d74725_1 conda-forge terminado 0.12.1 py39hcbf5309_1 conda-forge testpath 0.5.0 pyhd8ed1ab_0 conda-forge theano-pymc 1.1.2 pypi_0 pypi threadpoolctl 3.0.0 pyh8a188c0_0 conda-forge tk 8.6.11 h8ffe710_1 conda-forge toml 0.10.2 pyhd8ed1ab_0 conda-forge tornado 6.1 py39hb82d6ee_2 conda-forge tqdm 4.62.3 pyhd8ed1ab_0 conda-forge traitlets 5.1.1 pyhd8ed1ab_0 conda-forge typing-extensions 3.10.0.2 hd8ed1ab_0 conda-forge typing_extensions 3.10.0.2 pyha770c72_0 conda-forge tzdata 2021e he74cb21_0 conda-forge ucrt 10.0.20348.0 h57928b3_0 conda-forge ujson 4.2.0 py39h415ef7b_1 conda-forge urllib3 1.26.7 pyhd8ed1ab_0 conda-forge vc 14.2 hb210afc_5 conda-forge vs2015_runtime 14.29.30037 h902a5da_5 conda-forge wcwidth 0.2.5 pyh9f0ad1d_2 conda-forge webencodings 0.5.1 py_1 conda-forge websocket-client 1.2.1 py39hcbf5309_0 conda-forge wheel 0.37.0 pyhd8ed1ab_1 conda-forge win_inet_pton 1.1.0 py39hcbf5309_3 conda-forge winpty 0.4.3 4 conda-forge wrapt 1.13.3 py39hb82d6ee_1 conda-forge xarray 0.20.1 pyhd8ed1ab_0 conda-forge xorg-kbproto 1.0.7 hcd874cb_1002 conda-forge xorg-libice 1.0.10 hcd874cb_0 conda-forge xorg-libsm 1.2.3 hcd874cb_1000 conda-forge xorg-libx11 1.7.2 hcd874cb_0 conda-forge xorg-libxau 1.0.9 hcd874cb_0 conda-forge xorg-libxdmcp 1.1.3 hcd874cb_0 conda-forge xorg-libxext 1.3.4 hcd874cb_1 conda-forge xorg-libxpm 3.5.13 hcd874cb_0 conda-forge xorg-libxt 1.2.1 hcd874cb_2 conda-forge xorg-xextproto 7.3.0 hcd874cb_1002 conda-forge xorg-xproto 7.0.31 hcd874cb_1007 conda-forge xz 5.2.5 h62dcd97_1 conda-forge yaml 0.2.5 he774522_0 conda-forge yaml-cpp 0.6.3 ha925a31_4 conda-forge yapf 0.31.0 pyhd8ed1ab_0 conda-forge zeromq 4.3.4 h0e60522_1 conda-forge zipp 3.6.0 pyhd8ed1ab_0 conda-forge zlib 1.2.11 h8ffe710_1013 conda-forge zstd 1.5.0 h6255e5f_0 conda-forge ```

Details about conda and system ( conda info ):

``` $ conda info (removed paths with my name) active environment : base shell level : 1 conda version : 4.11.0 conda-build version : not installed python version : 3.9.7.final.0 virtual packages : __cuda=11.4=0 __win=0=0 __archspec=1=x86_64 platform : win-64 user-agent : conda/4.11.0 requests/2.26.0 CPython/3.9.7 Windows/10 Windows/10.0.19042 administrator : False netrc file : None offline mode : False ```