review (S) for 6930398: fix for return address locals in OSR entries uses wrong test

[Tom Rodriguez]

http://cr.openjdk.java.net/~never/6930398

6930398: fix for return address locals in OSR entries uses wrong test
Reviewed-by:

The fix for 6915557 is attempting to handle locals containing return
address specially but the test it's using is wrong.  C2's type system
smears together T_ADDRESS with raw pointer types, so
TypePtr::NULL_PTr->basic_type() == T_ADDRESS so the logic will trigger
for locals which are provably null resulting in asserts later.  The
correct fix is to test the ciType of the local which correctly
distinguishes these cases.  Tested with failing tests from nightly.

src/share/vm/opto/parse1.cpp