hg: loom/loom: correct FRAMES_TO_NOTIFY_POP value from 8 to 7 (after enter0 was removed)

[serguei.spitsyn at oracle.com]

Changeset: 4cee8d516376
Author:    sspitsyn
Date:      2019-06-06 02:23 -0700
URL:       http://hg.openjdk.java.net/loom/loom/rev/4cee8d516376

correct FRAMES_TO_NOTIFY_POP value from 8 to 7 (after enter0 was removed)

! test/hotspot/jtreg/serviceability/jvmti/ContinuationTest/libContinuationTest.cpp