[11u] RFR 8246274 and 8245511: G1 adaptive IHOP does not account for reclamation of humongous objects by young GC

[Kemper, William]

This fix went in originally as two changes, so there are two backports.


Original bug:

  https://bugs.openjdk.java.net/browse/JDK-8245511

  https://hg.openjdk.java.net/jdk/jdk/rev/d2eafcf20079


Depends on:

  https://bugs.openjdk.java.net/browse/JDK-8246274

  https://hg.openjdk.java.net/jdk/jdk/rev/69c5e17adacd


Patches applied cleanly.


11u webrev:

https://cr.openjdk.java.net/~phh/8245511/webrev.11u.01/

https://cr.openjdk.java.net/~phh/8246274/webrev.11u.01/?


Testing: x86_64 build, tier1, tier1_gc, tier2


Thank you,

William