6420645: Create a vm that uses compressed oops for up to 32gb heapsizes

Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv

Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold

hotspot/src/share/vm/oops/cpCacheOop.cpp

@@ -218,6 +218,7 @@ class LocalOopClosure: public OopClosure {
  public:
   LocalOopClosure(void f(oop*))        { _f = f; }
   virtual void do_oop(oop* o)          { _f(o); }
+  virtual void do_oop(narrowOop *o)    { ShouldNotReachHere(); }
 };