[9] RFR (XS) 8066199: C2 escape analysis prevents VM from exiting quickly

[Vladimir Kozlov]

http://cr.openjdk.java.net/~kvn/8066199/webrev/
https://bugs.openjdk.java.net/browse/JDK-8066199

Check for safepoint and block during EA Connection graph construction.

Aleksey Shipilev verify the fix.

Thanks,
Vladimir