Front-end: use separate flag for -swift-module-file instead of EQ

Author: nkcsgexi

include/swift/Option/FrontendOptions.td

@@ -217,8 +217,9 @@ def enable_resilience : Flag<["-"], "enable-resilience">,
 def disable_implicit_swift_modules: Flag<["-"], "disable-implicit-swift-modules">,
   HelpText<"Disable building Swift modules explicitly by the compiler">;
 
-def swift_module_file_EQ : Joined<["-"], "swift-module-file=">,
-  HelpText<"Specify Swift module explicitly built from textual interface">;
+def swift_module_file
+  : Separate<["-"], "swift-module-file">, MetaVarName<"<path>">,
+    HelpText<"Specify Swift module explicitly built from textual interface">;
 }
 
 

lib/Frontend/CompilerInvocation.cpp

@@ -865,7 +865,7 @@ static bool ParseSearchPathArgs(SearchPathOptions &Opts,
   Opts.DisableModulesValidateSystemDependencies |=
       Args.hasArg(OPT_disable_modules_validate_system_headers);
 
-  for (auto A: Args.filtered(OPT_swift_module_file_EQ)) {
+  for (auto A: Args.filtered(OPT_swift_module_file)) {
     Opts.ExplicitSwiftModules.push_back(resolveSearchPath(A->getValue()));
   }
   // Opts.RuntimeIncludePath is set by calls to

lib/Frontend/ModuleInterfaceLoader.cpp

@@ -1207,7 +1207,8 @@ InterfaceSubContextDelegateImpl::InterfaceSubContextDelegateImpl(
   // Adding these argumnets may not be necessary.
   // FIXME: remove it?
   for (auto EM: searchPathOpts.ExplicitSwiftModules) {
-    GenericArgs.push_back(ArgSaver.save((llvm::Twine("-swift-module-file=") + EM).str()));
+    GenericArgs.push_back("-swift-module-file");
+    GenericArgs.push_back(ArgSaver.save(EM));
   }
   if (clangImporter) {
     // We need to add these extra clang flags because explict module building