8067662: "java.lang.NullPointerException: Method name is null" from StackTraceElement.<init>
Summary: update java/lang/instrument/RedefineMethodInBacktrace.sh test to cover the hotspot fix
Reviewed-by: coleenp, dcubed

8025238: nsk/jvmti/scenarios/bcinstr/BI04/bi04t002 crashed with SIGSEGV
Summary: Redefined class in stack trace may not be found by method_idnum so handle null.
Reviewed-by: coleenp, dcubed, sspitsyn