[flang] flang doesn't correctly handle `-mframe-pointer=reserved`

[dpaoliello]

Clang recently started using FramePointerKind::Reserved for Arm64 Windows: #146582

Flang translates this to -mframe-pointer=reserved:

llvm-project/clang/lib/Driver/ToolChains/Flang.cpp

Lines 944 to 946 in 925588c

	case CodeGenOptions::FramePointerKind::Reserved:
	FPKeepKindStr = "-mframe-pointer=reserved";
	break;

However, Flang's command line parser doesn't handle -mframe-pointer=reserved (from https://lab.llvm.org/buildbot/#/builders/207/builds/3284):

FAILED: include/flang/__fortran_builtins.mod C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/build/include/flang/__fortran_builtins.mod 
C:\WINDOWS\system32\cmd.exe /C "cd /D C:\Users\tcwg\llvm-worker\flang-arm64-windows-msvc\build\tools\flang\tools\f18 && C:\Users\tcwg\scoop\apps\cmake\3.29.2\bin\cmake.exe -E make_directory C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/build/include/flang && C:\Users\tcwg\llvm-worker\flang-arm64-windows-msvc\build\bin\flang.exe -cpp -fsyntax-only -module-dir C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/build/include/flang C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/flang/module/__fortran_builtins.f90"
error: invalid value 'reserved' in '-mframe-pointer=reserved'

[llvmbot]

@llvm/issue-subscribers-flang-driver

Author: Daniel Paoliello (dpaoliello)

Clang recently started using `FramePointerKind::Reserved` for Arm64 Windows: #146582

Flang translates this to -mframe-pointer=reserved:

llvm-project/clang/lib/Driver/ToolChains/Flang.cpp

Lines 944 to 946 in 925588c

	case CodeGenOptions::FramePointerKind::Reserved:
	FPKeepKindStr = "-mframe-pointer=reserved";
	break;

However, Flang's command line parser doesn't handle -mframe-pointer=reserved (from <https://lab.llvm.org/buildbot/#/builders/207/builds/3284>):

FAILED: include/flang/__fortran_builtins.mod C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/build/include/flang/__fortran_builtins.mod 
C:\WINDOWS\system32\cmd.exe /C "cd /D C:\Users\tcwg\llvm-worker\flang-arm64-windows-msvc\build\tools\flang\tools\f18 && C:\Users\tcwg\scoop\apps\cmake\3.29.2\bin\cmake.exe -E make_directory C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/build/include/flang && C:\Users\tcwg\llvm-worker\flang-arm64-windows-msvc\build\bin\flang.exe -cpp -fsyntax-only -module-dir C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/build/include/flang C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/flang/module/__fortran_builtins.f90"
error: invalid value 'reserved' in '-mframe-pointer=reserved'

[pawosm-arm]

count me in, we're hitting that too in our CI