RFR(S) 8030955: assert(_prologue != NULL) failed: prologue pointer must be initialized

[harold seigel]

Hi,

Please review this backport to JDK8u of the JDK 9 hotspot fix for bug 
JDK-8030955.  This backport was tested with the jtreg hotspot tests, ute 
quick tests, and the accompanying test.

The bug: https://bugs.openjdk.java.net/browse/JDK-8030955
Open webrev: http://cr.openjdk.java.net/~hseigel/bug_8030955_8u/

Thanks! Harold