[8u] RFR 8187078: -XX:+VerifyOops finds numerous problems when running JPRT

[Aleksey Shipilev]

Original fix:
  https://bugs.openjdk.java.net/browse/JDK-8187078
  https://hg.openjdk.java.net/jdk/jdk/rev/8f594f75e054

The patch applies after reshuffles, except for barrierSetC1.cpp hunk, that is in c1_LIRGenerator.cpp
in 8u. (It was moved by a huge JDK-8201543 later in 11).

Testing: tier1, ad-hoc -XX:+VerifyOops tests

-- 
Thanks,
-Aleksey