[llvm] [Offload] Add MPI Plugin (PR #90890)

[Jhonatan Cléto via llvm-commits]

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@@ -1,5 +1,7 @@
 // RUN: %libomptarget-compile-run-and-check-generic
 
+// UNSUPPORTED: x86_64-pc-linux-gnu-mpi
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cl3to wrote:

In this patch, we do not intend to support shared/unified memory, so we have disabled tests for this functionality. We also did not intend to support pinned memory on the host, but I will add a naive implementation in this patch. However, for it to work, we have to wait for the fix in #91134 to be approved.

We disabled the tests `offload/test/api/omp_indirect_call.c` because our plugin is incompatible with the Device Environment features at this time.

When we introduce support for offloading to other remote accelerators, we will add these currently unsupported features.

https://github.com/llvm/llvm-project/pull/90890