Add support for calls to dependent names within templates, e.g.,

  template<typename T> void f(T x) {
    g(x); // g is a dependent name, so don't even bother to look it up
    g(); // error: g is not a dependent name
  }

Note that when we see "g(", we build a CXXDependentNameExpr. However,
if none of the call arguments are type-dependent, we will force the
resolution of the name "g" and replace the CXXDependentNameExpr with
its result.

GCC actually produces a nice error message when you make this
mistake, and even offers to compile your code with -fpermissive. I'll
do the former next, but I don't plan to do the latter.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60618 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprCXX.cpp b/lib/AST/ExprCXX.cpp
index 2d51719..b5d5b4c 100644
--- a/lib/AST/ExprCXX.cpp
+++ b/lib/AST/ExprCXX.cpp
@@ -112,6 +112,14 @@
 Stmt::child_iterator CXXDeleteExpr::child_begin() { return &Argument; }
 Stmt::child_iterator CXXDeleteExpr::child_end() { return &Argument+1; }
 
+// CXXDependentNameExpr
+Stmt::child_iterator CXXDependentNameExpr::child_begin() { 
+  return child_iterator(); 
+}
+Stmt::child_iterator CXXDependentNameExpr::child_end() {
+  return child_iterator();
+}
+
 OverloadedOperatorKind CXXOperatorCallExpr::getOperator() const {
   // All simple function calls (e.g. func()) are implicitly cast to pointer to
   // function. As a result, we try and obtain the DeclRefExpr from the