Note: issue is C2 specific.

It reproduced on linux,solaris, i586, amd64, sparc. I did not check windows.

To reproduce (with jdk6u18) run:
/net/vmsqe.russia/export/jdk/re/6u18/promoted/ea/b01/binaries/solaris-amd64/fastdebug/bin/java -server -d64 -XX:-ShowMessageBoxOnError     -Xverify:all  -XX:+CompileTheWorld -Xbootclasspath/p:/net/vmsqe.russia/export/testbase/ctw/build/../jars/ctw/jarfiles/java40.jar
...
Ouptut;
CompileTheWorld (200) : netscape/plugin/composer/PluginKiller
# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc:  SuppressErrorAt=/ciTypeFlow.cpp:2490
#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/BUILD_AREA/jdk6_18/hotspot/src/share/vm/ci/ciTypeFlow.cpp:2490), pid=4902, tid=9
#  Error: assert(lp != 0L,"nested loop must have parent by now")
#
# JRE version: 6.0_18-b01
# Java VM: Java HotSpot(TM) 64-Bit Server VM (16.0-b08-fastdebug mixed mode solaris-amd64 )
# An error report file with more information is saved as:
# /tmp/hs_err_pid4902.log
#
# If you would like to submit a bug report, please visit:
#   http://java.sun.com/webapps/bugreport/crash.jsp
#
Current thread is 9
Dumping core ...
Abort