8207006: serviceability/sa/TestUniverse.java#id0 crashes with EpsilonGC and AOT

[Aleksey Shipilev]

(This is cross-cutting compiler and GC, so posting at hotspot-dev@)

Bug:
  https://bugs.openjdk.java.net/browse/JDK-8207006

All uses of ci_card_table_address() outside of CardTableBarrierSet itself check
is_a(BarrierSet::CardTableBarrierSet) before reaching for card table address. Epsilon does not have
a card table, so unguarded check would assert in fastdebug, and crash in release.

Trivial fix:
  http://cr.openjdk.java.net/~shade/8207006/webrev.01/

I would like to push this to jdk/jdk11 but I am puzzled to how do that. Do I need to seek another
approval for jdk/jdk11? Do I push to both jdk/jdk and jdk/jdk11? Or just to jdk/jdk11, and it gets
forward-ported automatically?

Testing: tier1_compiler (which seems to include AOT tests), HelloWorld AOT+Epsilon, jdk-submit (running)

Thanks,
-Aleksey