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.

glslang/MachineIndependent/ParseHelper.h

@@ -145,6 +145,8 @@ public:
     virtual bool lValueErrorCheck(const TSourceLoc&, const char* op, TIntermTyped*);
     virtual void rValueErrorCheck(const TSourceLoc&, const char* op, TIntermTyped*);
 
+    const char* const scopeMangler = "::";
+
 protected:
     TParseContextBase(TParseContextBase&);
     TParseContextBase& operator=(TParseContextBase&);