A single line backport from jdk/jdk:
4171 // Verification can't be applied to fully built strip mined loops
4172 head->as_Loop()->outer_loop_end()->in(1)->find_int_con(-1) == 0) {
makes a bunch of shared code changes useless:
http://cr.openjdk.java.net/~roland/shenandoah/jdk11-cleanup2/webrev.00/
Roland.