review(S): 7042153: guarantee(x_compare_res != Constant::not_comparable) failed: incomparable constants in IfOp

[Vladimir Kozlov]

Looks good to me. I would add a comment for changes in c1_Optimizer.cpp to 
explain why !can_trap() check is needed.

Vladimir

Igor Veresov wrote:
> In C1, during IfOp elimination we can try to fold and IfOp that has 
> constant objects as an arguments to the condition that are unloaded (not 
> known at compile time) and are going to be patched later.
> The solution is to check for such cases in make_ifop().
> 
> Webrev: http://cr.openjdk.java.net/~iveresov/7042153/webrev.00/
> 
> Tested with a short testcase, which I added to the regression suite.
> 
> Thanks,
> igor