Correctly track tags and enum members defined in the prototype of a function, and ensure they are properly scoped.

This fixes code such as:

enum e {x, y};
int f(enum {y, x} n) {
  return 0;
}

This finally fixes PR5464 and PR5477.

llvm-svn: 151638
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 433ce10..bd75799 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -1847,6 +1847,16 @@
   }
 }
 
+void FunctionDecl::setDeclsInPrototypeScope(llvm::ArrayRef<NamedDecl *> NewDecls) {
+  assert(DeclsInPrototypeScope.empty() && "Already has prototype decls!");
+
+  if (!NewDecls.empty()) {
+    NamedDecl **A = new (getASTContext()) NamedDecl*[NewDecls.size()];
+    std::copy(NewDecls.begin(), NewDecls.end(), A);
+    DeclsInPrototypeScope = llvm::ArrayRef<NamedDecl*>(A, NewDecls.size());
+  }
+}
+
 /// getMinRequiredArguments - Returns the minimum number of arguments
 /// needed to call this function. This may be fewer than the number of
 /// function parameters, if some of the parameters have default
diff --git a/clang/lib/AST/DumpXML.cpp b/clang/lib/AST/DumpXML.cpp
index b4038dd..b180e80 100644
--- a/clang/lib/AST/DumpXML.cpp
+++ b/clang/lib/AST/DumpXML.cpp
@@ -497,6 +497,10 @@
     for (FunctionDecl::param_iterator
            I = D->param_begin(), E = D->param_end(); I != E; ++I)
       dispatch(*I);
+    for (llvm::ArrayRef<NamedDecl*>::iterator
+           I = D->getDeclsInPrototypeScope().begin(), E = D->getDeclsInPrototypeScope().end();
+         I != E; ++I)
+      dispatch(*I);
     if (D->doesThisDeclarationHaveABody())
       dispatch(D->getBody());
   }