Make TypeDecl much less friendly.

llvm-svn: 207007
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index dd7b0c8..f3a4ff3 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -3202,8 +3202,8 @@
 
 void TagDecl::setTypedefNameForAnonDecl(TypedefNameDecl *TDD) {
   NamedDeclOrQualifier = TDD;
-  if (TypeForDecl)
-    assert(TypeForDecl->isLinkageValid());
+  if (const Type *T = getTypeForDecl())
+    assert(T->isLinkageValid());
   assert(isLinkageValid());
 }