HLSL non-functional: Generalize namespace nesting.

Also use this to move deferred member-function-body parsing to a better
place.

This should also be well poised for implementing the 'namespace' keyword.

hlsl/hlslAttributes.h

@@ -95,9 +95,11 @@ namespace glslang {
 
     class TFunctionDeclarator {
     public:
+        TFunctionDeclarator() : function(nullptr), body(nullptr) { }
         TSourceLoc loc;
         TFunction* function;
         TAttributeMap attributes;
+        TVector<HlslToken>* body;
     };
 
 } // end namespace glslang