The following tests are failing on MacOSX in the JDK12 CI:

runtime/appcds/javaldr/GCSharedStringsDuringDump.java
runtime/appcds/javaldr/GCDuringDump.java
runtime/RedefineTests/RedefineRunningMethods.java

Here's a snippet of the crash:

# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x00007fff78126460, pid=10928, tid=13315
#
# JRE version: Java(TM) SE Runtime Environment (12.0) (fastdebug build 12-internal+0-jdk12-jdk.150)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 12-internal+0-jdk12-jdk.150, interpreted mode, compressed oops, g1 gc, bsd-amd64)
# Problematic frame:
# C [libsystem_platform.dylib+0x1460] _platform_memmove$VARIANT$Nehalem+0x60