Fix activate scripts for dpcpp compiler

[isuruf]

Checklist

• [ ] Used a personal fork of the feedstock to propose changes
• [ ] Bumped the build number (if the version is unchanged)
• [ ] Reset the build number to 0 (if the version changed)
• [ ] Re-rendered with the latest conda-smithy (Use the phrase code>@<space/conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• [ ] Ensured the license file is being packaged.

[conda-forge-webservices[bot]]

Hi! This is the friendly automated conda-forge-linting service.

I wanted to let you know that I linted all conda-recipes in your PR (recipe) and found some lint.

Here's what I've got...

For recipe:

• When defining a source/url please add a sha256, sha1 or md5 checksum (sha256 preferably).
• When defining a source/url please add a sha256, sha1 or md5 checksum (sha256 preferably).
• When defining a source/url please add a sha256, sha1 or md5 checksum (sha256 preferably).
• When defining a source/url please add a sha256, sha1 or md5 checksum (sha256 preferably).
• When defining a source/url please add a sha256, sha1 or md5 checksum (sha256 preferably).
• When defining a source/url please add a sha256, sha1 or md5 checksum (sha256 preferably).
• When defining a source/url please add a sha256, sha1 or md5 checksum (sha256 preferably).
• When defining a source/url please add a sha256, sha1 or md5 checksum (sha256 preferably).
• pin_compatible should be used instead of pin_subpackage for dpcpp_impl_win-64 because it is not a known output of this recipe: ['intel-cmplr-lic-rt', 'intel-cmplr-lib-rt', 'intel-fortran-rt', 'intel-opencl-rt', 'dpcpp-cpp-rt', 'dpcpp_impl_linux-64', 'dpcpp_linux-64', 'oneccl-devel', 'intel-compiler-repack'].

[napetrov]

Hi @isuruf - is there content for this PR? Not sure I understand everything here

[oleksandr-pavlyk]

Yes, a context would be nice.

Instead of specifying --gcc-toolchain, --sysroot, and --target in $CFLAGS, we leverage support for compiler configuration files:

# Intel LLVM must cooperate with compiler and sysroot from conda
echo "--gcc-toolchain=${BUILD_PREFIX} --sysroot=${BUILD_PREFIX}/${HOST}/sysroot -target ${HOST}" > icpx_for_conda.cfg
export ICPXCFG="$(pwd)/icpx_for_conda.cfg"
export ICXCFG="$(pwd)/icpx_for_conda.cfg"

Perhaps this could be used in the compiler activation script.

[isuruf]

This is for https://github.com/conda-forge/onednn-feedstock/pull/53. Yeah we can use that script.

[isuruf]

@napetrov can you review and merge?