RFR(XS): 8144852: Corrupted oop in nmethod

[Dean Long]

https://bugs.openjdk.java.net/browse/JDK-8144852
http://cr.openjdk.java.net/~dlong//8144852/webrev/

The fix for [1] introduced new functions nmethod::print_recorded_oops 
and nmethod::print_recorded_metadata that print all oop and metadata 
values in an nmethod.  Currently NULL values are handled OK, but 
Universe::non_oop_word values cause a crash.

(This bug is marked confidential because it was reported against one of 
our closed ports.)

dl

[1]     JDK-8072008: Emit direct call instead of linkTo* for recursive 
indy/MH.invoke* calls