initial rust mpi support #6036

Job	Run time
Enzyme CI LLVM 11 Release ubuntu-20.04	5m 11s
Enzyme CI LLVM 12 Release macOS	3m 53s
Enzyme CI LLVM 11 Debug ubuntu-20.04	5m 11s
Enzyme CI LLVM 12 Debug macOS	4m 3s
Enzyme CI LLVM 12 Release ubuntu-20.04	5m 20s
Enzyme CI LLVM 13 Release macOS	3m 46s
Enzyme CI LLVM 12 Debug ubuntu-20.04	4m 33s
Enzyme CI LLVM 13 Release ubuntu-20.04	5m 8s
Enzyme CI LLVM 13 Debug macOS	3m 40s
Enzyme CI LLVM 13 Debug ubuntu-20.04	4m 21s
Enzyme CI LLVM 14 Release macOS	4m 14s
Enzyme CI LLVM 14 Release ubuntu-20.04	5m 16s
Enzyme CI LLVM 14 Debug ubuntu-20.04	4m 26s
Enzyme CI LLVM 14 Debug macOS	5m 34s
Enzyme CI LLVM 15 Release ubuntu-20.04	5m 14s
Enzyme CI LLVM 15 Release macOS	3m 58s
Enzyme CI LLVM 15 Debug macOS	3m 47s
Enzyme CI LLVM 15 Debug ubuntu-20.04	4m 34s
Enzyme CI LLVM 16 Release ubuntu-20.04	5m 7s
Enzyme CI LLVM 16 Release macOS	3m 57s
Enzyme CI LLVM 16 Debug macOS	5m 4s
Enzyme CI LLVM 16 Debug ubuntu-20.04	4m 17s
Enzyme CI LLVM 13 Release macOS XCode	4m 43s
	1h 45m 17s

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