[libc] [llvm] [libc] Add RPC helpers for dispatching functions to the host (PR #179085)

[Shilei Tian via llvm-commits]

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@@ -590,7 +623,6 @@ RPC_ATTRS Server::Port Server::open(uint32_t lane_size) {
   }
 }
 
-#undef RPC_ATTRS
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shiltian wrote:

Guess at one point we still need to do this; otherwise it is leaked.

https://github.com/llvm/llvm-project/pull/179085