[9] RFR(S): 8144487: PhaseIdealLoop::build_and_optimize() must restore major_progress flag if skip_loop_opts is true

[Tobias Hartmann]

Hi,

please review the following patch.

https://bugs.openjdk.java.net/browse/JDK-8144487
http://cr.openjdk.java.net/~thartmann/8144487/webrev.00/

The fix for JDK-7107042 introduced a 'skip_loop_opts' flag for PhaseIdealLoop::build_and_optimize() to not execute loop optimizations before EA. We need to restore the major_progress flag before calling igvn.optimize() because other code depends on the fact that we don't execute more loop optimizations if major_progress() is not set (for example, in ConvI2LNode::Ideal).

Thanks,
Tobias