[11u] RFR 8230000: some httpclients testng tests run zero test

[Aleksey Shipilev]

Original fix:
  https://bugs.openjdk.java.net/browse/JDK-8230000
  https://hg.openjdk.java.net/jdk/jdk/rev/ff08db52ad92

The patch applies to 11u with a minor conflict in AbstractThrowingPushPromises.java, which I
resolved by reapplying the hunks by hand.

11u webrev:
  https://cr.openjdk.java.net/~shade/8230000/webrev.11u.01/

Testing: jdk/java/net/httpclient tests

-- 
Thanks,
-Aleksey