The failure seems to be due to a slow machine.
It's definitely not a deadlock in initialization (see JDK-8072466), as that was specific to Windows, and the test failure was observed on Linux.

ACTION: main -- Failed. Execution failed: `main' threw exception: java.lang.RuntimeException: Failed to complete on time.
REASON: User specified action: run main/othervm MultiDead
TIME: 20.734 seconds
messages:
command: main MultiDead
reason: User specified action: run main/othervm MultiDead
elapsed time (seconds): 20.734
STDOUT:
child #1 of 20
child #2 of 20
child #3 of 20
child #4 of 20
child #5 of 20
child #6 of 20
child #7 of 20
child #8 of 20
child #9 of 20
child #10 of 20
child #11 of 20
child #12 of 20
child #13 of 20
child #14 of 20
child #15 of 20
child #16 of 20
child #17 of 20
child #18 of 20
STDERR:
java.lang.RuntimeException: Failed to complete on time.
at MultiDead.parentProcess(MultiDead.java:87)
at MultiDead.main(MultiDead.java:46)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:520)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:92)
at java.lang.Thread.run(Thread.java:747)

JavaTest Message: Test threw exception: java.lang.RuntimeException: Failed to complete on time.
JavaTest Message: shutting down test

STATUS:Failed.`main' threw exception: java.lang.RuntimeException: Failed to complete on time.