hg: jdk/sandbox: 8202949: C2: assert(false) failed: Bad graph detected in build_loop_late

[chris.hegarty at oracle.com]

Changeset: 131a631b271a
Author:    thartmann
Date:      2018-05-25 09:05 +0200
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/131a631b271a

8202949: C2: assert(false) failed: Bad graph detected in build_loop_late
Summary: Fixed trip count computation for counted loop with negative stride to prevent over-unrolling.
Reviewed-by: roland

! src/hotspot/share/opto/loopTransform.cpp
! test/hotspot/jtreg/compiler/loopopts/TestOverunrolling.java