Fix our semantic analysis of

  unqualified-id '('

in C++. The unqualified-id might not refer to any declaration in our
current scope, but declarations by that name might be found via
argument-dependent lookup. We now do so properly.

As part of this change, CXXDependentNameExpr, which was previously
designed to express the unqualified-id in the above constructor within
templates, has become UnresolvedFunctionNameExpr, which does
effectively the same thing but will work for both templates and
non-templates.

Additionally, we cope with all unqualified-ids, since ADL also applies
in cases like

  operator+(x, y)




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63733 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/StmtSerialization.cpp b/lib/AST/StmtSerialization.cpp
index 8599a7a..3bb98b4 100644
--- a/lib/AST/StmtSerialization.cpp
+++ b/lib/AST/StmtSerialization.cpp
@@ -245,8 +245,8 @@
     case CXXDeleteExprClass:
       return CXXDeleteExpr::CreateImpl(D, C);
 
-    case CXXDependentNameExprClass:
-      return CXXDependentNameExpr::CreateImpl(D, C);
+    case UnresolvedFunctionNameExprClass:
+      return UnresolvedFunctionNameExpr::CreateImpl(D, C);
 
     case CXXCatchStmtClass:
       return CXXCatchStmt::CreateImpl(D, C);
@@ -1528,18 +1528,18 @@
                            cast<Expr>(Argument), Loc);
 }
 
-void CXXDependentNameExpr::EmitImpl(llvm::Serializer& S) const {
+void UnresolvedFunctionNameExpr::EmitImpl(llvm::Serializer& S) const {
   S.Emit(getType());
-  S.EmitPtr(Name);
+  S.EmitPtr(Name.getAsIdentifierInfo()); // FIXME: WRONG!
   S.Emit(Loc);
 }
 
-CXXDependentNameExpr *
-CXXDependentNameExpr::CreateImpl(llvm::Deserializer& D, ASTContext& C) {
+UnresolvedFunctionNameExpr *
+UnresolvedFunctionNameExpr::CreateImpl(llvm::Deserializer& D, ASTContext& C) {
   QualType Ty = QualType::ReadVal(D);
   IdentifierInfo *N = D.ReadPtr<IdentifierInfo>();
   SourceLocation L = SourceLocation::ReadVal(D);
-  return new CXXDependentNameExpr(N, Ty, L);
+  return new UnresolvedFunctionNameExpr(N, Ty, L);
 }
 
 void UnaryTypeTraitExpr::EmitImpl(llvm::Serializer& S) const {