[clang] [clang] Introduce `SemaOpenMP` (PR #88642)

[Vlad Serebrennikov via cfe-commits]

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@@ -997,6 +987,11 @@ class Sema final : public SemaBase {
     return *OpenACCPtr;
   }
 
+  SemaOpenMP &OpenMP() {
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Endilll wrote:

This was discussed back when we started splitting `Sema` up: https://github.com/llvm/llvm-project/pull/84184#discussion_r1520027821. We can reopen the discussion if you insist, otherwise I'd like to keep it consistent with CUDA, HLSL, etc.

https://github.com/llvm/llvm-project/pull/88642