RFR: 8224815: Remove non-GC uses of CollectedHeap::is_in_reserved()

[Erik Österlund]

Hi,

The CollectedHeap::is_in_reserved() function assumes the GC has a 
contiguous heap. This might not be the case, and hence the shared code 
should not make assumptions about that. It should use 
CollectedHeap::is_in() instead.

However, CompressedOops inherently assumes the heap is contiguous, so I 
let it know about the reserved region.

This patch depends on 8229278 and 8229189, which are both out for review 
right now.

Bug:
https://bugs.openjdk.java.net/browse/JDK-8224815

Webrev:
http://cr.openjdk.java.net/~eosterlund/8224815/webrev.00/

Thanks,
/Erik