AST: Resolve an unused field warning in ClangImporter.cpp.

Author: tshortli

lib/ClangImporter/ClangImporter.cpp

@@ -188,18 +188,16 @@ namespace {
   };
 
   class ParsingAction : public clang::ASTFrontendAction {
-    ASTContext &Ctx;
     ClangImporter &Importer;
     ClangImporter::Implementation &Impl;
     const ClangImporterOptions &ImporterOpts;
     std::string SwiftPCHHash;
   public:
-    explicit ParsingAction(ASTContext &ctx,
-                           ClangImporter &importer,
+    explicit ParsingAction(ClangImporter &importer,
                            ClangImporter::Implementation &impl,
                            const ClangImporterOptions &importerOpts,
                            std::string swiftPCHHash)
-      : Ctx(ctx), Importer(importer), Impl(impl), ImporterOpts(importerOpts),
+      : Importer(importer), Impl(impl), ImporterOpts(importerOpts),
         SwiftPCHHash(swiftPCHHash) {}
     std::unique_ptr<clang::ASTConsumer>
     CreateASTConsumer(clang::CompilerInstance &CI, StringRef InFile) override {
@@ -1477,7 +1475,7 @@ ClangImporter::create(ASTContext &ctx,
   }
 
   // Create the associated action.
-  importer->Impl.Action.reset(new ParsingAction(ctx, *importer,
+  importer->Impl.Action.reset(new ParsingAction(*importer,
                                                 importer->Impl,
                                                 importerOpts,
                                                 swiftPCHHash));