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/Sema/Sema.h b/lib/Sema/Sema.h
index 3143b5c..6b8d852 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -517,12 +517,13 @@
                                                    bool Complain);
   void FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn);
 
-  FunctionDecl *ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Func,
+  FunctionDecl *ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee,
+                                        DeclarationName UnqualifiedName,
                                         SourceLocation LParenLoc,
                                         Expr **Args, unsigned NumArgs,
                                         SourceLocation *CommaLocs, 
                                         SourceLocation RParenLoc,
-                                        bool ArgumentDependentLookup);
+                                        bool &ArgumentDependentLookup);
   ExprResult
   BuildCallToMemberFunction(Scope *S, Expr *MemExpr,
                             SourceLocation LParenLoc, Expr **Args, 
@@ -1068,7 +1069,6 @@
                                             DeclarationName Name,
                                             bool HasTrailingLParen,
                                             const CXXScopeSpec *SS,
-                                            bool ForceResolution = false,
                                             bool isAddressOfOperand = false);
 
   virtual OwningExprResult ActOnPredefinedExpr(SourceLocation Loc,