6964774: Adjust optimization flags setting Summary: Adjust performance flags settings. Reviewed-by: never, phh

6677629: PhaseIterGVN::subsume_node() should call hash_delete() and add_users_to_worklist() Summary: Use replace_node() method instead of subsume_node(). Reviewed-by: jrose, never

6964479: widen normalization of small int and long values should be symmetric Summary: normalize widen value in xmeet() and xdual() methods for types Int and Long so the type meet will be symmetric. Reviewed-by: jrose

Merge