[wasm] Remove implicit _WASI_EMULATED_X macro definition in ClangImporter

Author: kateinoigakukun

lib/ClangImporter/ClangImporter.cpp

@@ -663,10 +663,6 @@ importer::getNormalInvocationArguments(
     }
 
     if (triple.isOSWASI()) {
-      invocationArgStrs.insert(invocationArgStrs.end(),
-                               {"-D_WASI_EMULATED_MMAN",
-                                "-D_WASI_EMULATED_SIGNAL",
-                                "-D_WASI_EMULATED_PROCESS_CLOCKS"});
       SmallString<128> buffer;
       if (auto path = getWasiLibcModuleMapPath(searchPathOpts, triple, buffer)) {
         invocationArgStrs.push_back((Twine("-fmodule-map-file=") + *path).str());