[clang] [llvm] [openmp] [OpenMP] support for Emissary APIs as discussed in 89169 (PR #175265)

[via cfe-commits]

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@@ -41,6 +41,8 @@ set(core_files
   tgmath.h
   unwind.h
   varargs.h
+  EmissaryIds.h
+  EmissaryMPI.h
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LunNova wrote:

`core_files list contains the headers shared by all platforms.`

Adding two new all platforms .h files to core_files feels a bit dubious, shouldn't this be specific to offload platforms or -xhip in some way?

https://github.com/llvm/llvm-project/pull/175265