[8u] RFR 8237368: Problem with NullPointerException in RMI TCPEndpoint.read

[Aleksey Shipilev]

Original fix:
  https://bugs.openjdk.java.net/browse/JDK-8237368
  https://hg.openjdk.java.net/jdk/jdk14/rev/39df849b3896

This is a regression since last CPU. Patch does not apply cleanly to 8u due to reshuffling: both the
product fix and the test are in old places.

8u webrev:
  https://cr.openjdk.java.net/~shade/8237368/webrev.01/

Testing: jdk_rmi tests (new test fails before product fix, passes after)


-- 
Thanks,
-Aleksey