Please review (S) 6695819: verify_oop: rax: broken oop in decode_heap_oop

[Coleen Phillimore - Sun Microsystems]

Fixed 6695819: verify_oop: rax: broken oop in decode_heap_oop

Code in gen_subtype_check was encoding rax as an oop on a path where
rax was not an oop.
Also added verify_oop to sparc assembler, encode and decode heap oop.

Fix verified? (y/n) y
Verified by: ran with -XX:+VerifyOops Queens

Webrev:
http://webrev.invokedynamic.info/coleenp/6695819

Reviewed by: <please>

thanks,
Coleen