Recommit r359859 "[Attribute/Diagnostics] Print macro if definition is an attribute declaration"

Updated with fix for read of uninitialized memory.

llvm-svn: 360109
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 1eb5460..1dba7cc 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -1963,6 +1963,7 @@
   case Type::ObjCTypeParam:
   case Type::Atomic:
   case Type::Pipe:
+  case Type::MacroQualified:
     llvm_unreachable("type is illegal as a nested name specifier");
 
   case Type::SubstTemplateTypeParmPack: