Add entry for Apple M2

[alalazo]

@sethjr FYI

[alalazo]

FYI, I contacted people from the Asahi project in IRC chat yesterday, and they kindly posted a /proc/cpuinfo sample on Apple M2 at https://github.com/archspec/archspec/issues/95

[sethrj]

@alalazo on apple-clang@13.1.6 it looks like the native CPU type is vortex, and apple-m2 doesn't work. (It might be that this version was developed before the M2 was released, so it had a code name.) I confirmed that native and vortex give the same target CPU in the verbose output.

$ echo "void derp() {}" | clang -mcpu=native -c -S -v -x c++ - -o - 2>&1 | grep cpu
 "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang" -cc1 -triple arm64-apple-macosx12.0.0 -Wundef-prefix=TARGET_OS_ -Wdeprecated-objc-isa-usage -Werror=deprecated-objc-isa-usage -Werror=implicit-function-declaration -S -disable-free -disable-llvm-verifier -discard-value-names -main-file-name - -mrelocation-model pic -pic-level 2 -mframe-pointer=non-leaf -fno-strict-return -fno-rounding-math -munwind-tables -target-sdk-version=12.3 -fvisibility-inlines-hidden-static-local-var -target-cpu vortex -target-feature +v8.3a -target-feature +fp-armv8 -target-feature +neon -target-feature +crc -target-feature +crypto -target-feature +fullfp16 -target-feature +ras -target-feature +lse -target-feature +rdm -target-feature +rcpc -target-feature +zcm -target-feature +zcz -target-feature +sha2 -target-feature +aes -target-abi darwinpcs -fallow-half-arguments-and-returns -mllvm -treat-scalable-fixed-error-as-warning -debugger-tuning=lldb -target-linker-version 763 -v -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/13.1.6 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk -I/usr/local/include -stdlib=libc++ -internal-isystem /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1 -internal-isystem /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/local/include -internal-isystem /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/13.1.6/include -internal-externc-isystem /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include -internal-externc-isystem /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include -Wno-reorder-init-list -Wno-implicit-int-float-conversion -Wno-c99-designator -Wno-final-dtor-non-final-class -Wno-extra-semi-stmt -Wno-misleading-indentation -Wno-quoted-include-in-framework-header -Wno-implicit-fallthrough -Wno-enum-enum-conversion -Wno-enum-float-conversion -Wno-elaborated-enum-base -Wno-reserved-identifier -Wno-gnu-folding-constant -Wno-objc-load-method -fdeprecated-macro -fdebug-compilation-dir=/Users/seth -ferror-limit 19 -stack-protector 1 -fstack-check -mdarwin-stkchk-strong-link -fblocks -fencode-extended-block-signature -fregister-global-dtors-with-atexit -fgnuc-version=4.2.1 -fno-cxx-modules -fcxx-exceptions -fexceptions -fmax-type-align=16 -fcommon -clang-vendor-feature=+messageToSelfInClassMethodIdReturnType -clang-vendor-feature=+disableInferNewAvailabilityFromInit -clang-vendor-feature=+disableNonDependentMemberExprInCurrentInstantiation -fno-odr-hash-protocols -clang-vendor-feature=+enableAggressiveVLAFolding -clang-vendor-feature=+revert09abecef7bbf -clang-vendor-feature=+thisNoAlignAttr -clang-vendor-feature=+thisNoNullAttr -mllvm -disable-aligned-alloc-awareness=1 -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o - -x c++ -
$ echo "void derp() {}" | clang -mcpu=apple-m2 -c -S -v -x c++ - -o - 2>&1 | grep cpu
clang: error: the clang compiler does not support '-mcpu=apple-m2'

EDIT: for clarity, the cpu and features are:

-target-cpu vortex
-target-feature +v8.3a
-target-feature +fp-armv8
-target-feature +neon
-target-feature +crc
-target-feature +crypto
-target-feature +fullfp16
-target-feature +ras
-target-feature +lse
-target-feature +rdm
-target-feature +rcpc
-target-feature +zcm
-target-feature +zcz
-target-feature +sha2
-target-feature +aes

[alalazo]

I'm going to merge this. We can refine compiler flags in following PRs