review for 6730192 (S): expression stack wrong at deoptimization point

[Chuck Rasbold]

http://webrev.invokedynamic.info/rasbold/6730192/

6730192: expression stack wrong at deoptimization point
Summary: add safepoint before popping expression stack, not after
Reviewed-by:

A silly mistake from the recent change for 6726504. The expression
stack should be popped after adding the safepoint.