java heap mark bits expansion is broken

Because of the way mark bits space in the java heap is expanded, we can run out of
mark bits with object and handle space still available. This shows up under Solaris,
and part of the reason is sysCommitMem() rounds up the allocation to the nearest
pagesize. So even though the sum of the increments does not exceed the mapped
heap size, "markmax" can still be exceeded because of the accumulated roundup.

DREL 1/16/96