[clang] [clang][OpenMP] Add OpenMP GPU optimization flag framework (PR #178914)

[via cfe-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 52338 tests passed
* 926 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### Clang
<details>
<summary>Clang.Driver/openmp-target-fast-flag.c</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 3
c:\_work\llvm-project\llvm-project\build\bin\clang.exe -### -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx90a C:\_work\llvm-project\llvm-project\clang\test\Driver\openmp-target-fast-flag.c -O0 2>&1    | c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe -check-prefixes=DefaultTFast,DefaultEnV,DefaultTState,DefaultNoNestParallel C:\_work\llvm-project\llvm-project\clang\test\Driver\openmp-target-fast-flag.c
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\clang.exe' '-###' -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx90a 'C:\_work\llvm-project\llvm-project\clang\test\Driver\openmp-target-fast-flag.c' -O0
# note: command had no output on stdout or stderr
# error: command failed with exit status: 1
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe' -check-prefixes=DefaultTFast,DefaultEnV,DefaultTState,DefaultNoNestParallel 'C:\_work\llvm-project\llvm-project\clang\test\Driver\openmp-target-fast-flag.c'
# note: command had no output on stdout or stderr

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/178914