Rename Selector::getName() to Selector::getAsString(), and add
a new NamedDecl::getAsString() method.

Change uses of Selector::getName() to just pass in a Selector 
where possible (e.g. to diagnostics) instead of going through
an std::string.

This also adds new formatters for objcinstance and objcclass
as described in the dox.

llvm-svn: 59933
diff --git a/clang/lib/AST/DeclarationName.cpp b/clang/lib/AST/DeclarationName.cpp
index 3a9e7c8..ed4b7c6 100644
--- a/clang/lib/AST/DeclarationName.cpp
+++ b/clang/lib/AST/DeclarationName.cpp
@@ -120,7 +120,7 @@
   case ObjCZeroArgSelector:
   case ObjCOneArgSelector:
   case ObjCMultiArgSelector:
-    return getObjCSelector().getName();
+    return getObjCSelector().getAsString();
 
   case CXXConstructorName: {
     QualType ClassType = getCXXNameType();