[OpenMP] Add match_{all,any,none} declare variant selector extensions.

By default, all traits in the OpenMP context selector have to match for
it to be acceptable. Though, we sometimes want a single property out of
multiple to match (=any) or no match at all (=none). We offer these
choices as extensions via
  `implementation={extension(match_{all,any,none})}`
to the user. The choice will affect the entire context selector not only
the traits following the match property.

The first user will be D75788. There we can replace
```
  #pragma omp begin declare variant match(device={arch(nvptx64)})
  #define __CUDA__

  #include <__clang_cuda_cmath.h>

  // TODO: Hack until we support an extension to the match clause that allows "or".
  #undef __CLANG_CUDA_CMATH_H__

  #undef __CUDA__
  #pragma omp end declare variant

  #pragma omp begin declare variant match(device={arch(nvptx)})
  #define __CUDA__

  #include <__clang_cuda_cmath.h>

  #undef __CUDA__
  #pragma omp end declare variant
```
with the much simpler
```
  #pragma omp begin declare variant match(device={arch(nvptx, nvptx64)}, implementation={extension(match_any)})
  #define __CUDA__

  #include <__clang_cuda_cmath.h>

  #undef __CUDA__
  #pragma omp end declare variant
```

Reviewed By: mikerice

Differential Revision: https://reviews.llvm.org/D77414

0 files changed, 0 insertions, 0 deletions