libc: Rename ERROR to RPC_ERROR to avoid conflict in windows build

Somehow conflict with define in wingdi.h.

Fix build failures:

[ 52%] Building CXX object projects/offload/plugins-nextgen/common/CMakeFiles/PluginCommon.dir/src/RPC.cpp.obj
In file included from ...llvm\offload\plugins-nextgen\common\src\RPC.cpp:16:
...\llvm\libc\shared\rpc.h(48,3): error: expected identifier
   48 |   ERROR = 0x1000,
      |   ^
c:\Program files (x86)\Windows Kits\10\include\10.0.22000.0\um\wingdi.h(118,29): note: expanded from macro 'ERROR'
  118 | #define ERROR               0
      |                             ^
...\llvm\offload\plugins-nextgen\common\src\RPC.cpp(75,17): error: expected unqualified-id
   75 |     return rpc::ERROR;
      |                 ^
c:\Program files (x86)\Windows Kits\10\include\10.0.22000.0\um\wingdi.h(118,29): note: expanded from macro 'ERROR'
  118 | #define ERROR               0
      |                             ^
2 errors generated.

Author: jsji

libc/shared/rpc.h

@@ -45,7 +45,7 @@ namespace rpc {
 /// Generic codes that can be used whem implementing the server.
 enum Status {
   SUCCESS = 0x0,
-  ERROR = 0x1000,
+  RPC_ERROR = 0x1000,
   UNHANDLED_OPCODE = 0x1001,
 };
 

libc/utils/gpu/server/rpc_server.cpp

@@ -455,7 +455,7 @@ rpc::Status handle_libc_opcodes(rpc::Server::Port &port, uint32_t num_lanes) {
   case 64:
     return handle_port_impl<64>(port);
   default:
-    return rpc::ERROR;
+    return rpc::RPC_ERROR;
   }
 }
 } // namespace rpc

offload/plugins-nextgen/common/src/RPC.cpp

@@ -72,7 +72,7 @@ static rpc::Status handle_offload_opcodes(plugin::GenericDeviceTy &Device,
   else if (NumLanes == 64)
     return handle_offload_opcodes<64>(Device, Port);
   else
-    return rpc::ERROR;
+    return rpc::RPC_ERROR;
 }
 
 RPCServerTy::RPCServerTy(plugin::GenericPluginTy &Plugin)