Add runtime options for large object space

Adds the two following options:
Option -XX:LargeObjectSpace={freelist, map, disabled}
Option -XX:LargeObjectThreshold=size specifies the size for which
primitive arrays are allocated in the large object space.

Added handling for large object space == null in collectors.

Fixed an error in the mem map space where we didn't use the page
aligned size LOS for bytes allocated, this resutled in heaps appearing
a bit smaller than they should be.

Change-Id: I6f17c3534b59e7dc68cd375153e7a846799b3da4