[Swift+WASM] Allow Wasm object format.

- This currently does nothing more than adopt the ELF conventions, but for the
   Wasm object file format.

lib/IRGen/IRGenModule.cpp

@@ -1033,6 +1033,7 @@ void IRGenModule::emitAutolinkInfo() {
 
   } else {
     assert((TargetInfo.OutputObjectFormat == llvm::Triple::ELF ||
+            TargetInfo.OutputObjectFormat == llvm::Triple::Wasm ||
             Triple.isOSCygMing()) &&
            "expected ELF output format or COFF format for Cygwin/MinGW");