RFR: 8206267: Unsafe publication of StubCodeDesc leads to crashes

[aph]

The StubCodeDesc constructor is unsychronized. However, it runs when
the C2 compiler thread is initializing. The compiler thread reads the
StubCodeDesc list while it is in an unstable state, resulting in a
read from an uninitialized pointer field and it then segfaults,
causing the VM to abort.

http://cr.openjdk.java.net/~aph/8206267/

OK for 11 and 12?

-- 
Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671