Put the post zygote non-moving space next to the malloc space.

This change fixes the following problem with the GSS collector: if the
post zygote non-moving space happens to be located after the bump
pointer spaces, the bump pointer space is treated wrongfully as an
immune space. The reasons are 1) the immune space is represented by a
simple address range and 2) the GSS collector treats the post zygote
non-moving space as an immune space at a bump pointer space only
collection.

In addition, this change makes it a reality that all the non-moving
spaces are adjacent, which we tend to assume in the code (eg. the
notion of the immune space represented by a simple address range.)
This should help avoid potential confusions in the future.

Fix a DCHECK failure where usable_size isn't set properly when
-XX:UseTLAB is used.

Change-Id: I585920e433744a390f87e9a25bef6114b2a4623f
4 files changed