hg: jdk9/hs/jdk: 8158237: JVMTI hides critical debug information for memory leak tracing

[coleen.phillimore at oracle.com]

Changeset: dfcdb0a45822
Author:    coleenp
Date:      2016-06-13 09:03 -0400
URL:       http://hg.openjdk.java.net/jdk9/hs/jdk/rev/dfcdb0a45822

8158237: JVMTI hides critical debug information for memory leak tracing
Summary: remove _backtrace as hidden field, original problem no longer exists
Reviewed-by: sspitsyn, jiangli

! test/com/sun/jdi/BacktraceFieldTest.java