hg: loom/loom: Add test to reproduce asserts when breakpointing and single stepping in Continuation.yield()

[chris.plummer at oracle.com]

Changeset: cfa1c3318401
Author:    cjplummer
Date:      2019-05-16 08:25 -0700
URL:       http://hg.openjdk.java.net/loom/loom/rev/cfa1c3318401

Add test to reproduce asserts when breakpointing and single stepping in Continuation.yield()

+ test/hotspot/jtreg/serviceability/jvmti/ContYieldBreakPointTest/MyPackage/ContYieldBreakPointTest.java
+ test/hotspot/jtreg/serviceability/jvmti/ContYieldBreakPointTest/libContYieldBreakPointTest.cpp