[llvm] [Offload] Add MPI Proxy Plugin (PR #114574)

[Hervé Yviquel via llvm-commits]

================
@@ -194,8 +194,10 @@ set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} powerpc64-ibm-linux-g
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} powerpc64-ibm-linux-gnu-LTO")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} x86_64-unknown-linux-gnu")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} x86_64-unknown-linux-gnu-LTO")
+set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} x86_64-unknown-linux-gnu-mpi")
----------------
hyviquel wrote:

So we are testing the support of the x86 and CUDA plugins with remote CPU/GPU using MPI as the communication layer

https://github.com/llvm/llvm-project/pull/114574