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/opto/node.hpp

@@ -917,6 +917,7 @@ public:
 
   // These guys are called by code generated by ADLC:
   intptr_t get_ptr() const;
+  intptr_t get_narrowcon() const;
   jdouble getd() const;
   jfloat getf() const;