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/utilities/debug.cpp

@@ -669,6 +669,7 @@ public:
       tty->print_cr("0x%08x", o);
     }
   }
+  void do_oop(narrowOop* o) { ShouldNotReachHere(); }
 };