8048112: G1 Full GC needs to support the case when the very first region is not available
Summary: Refactor preparation for compaction during Full GC so that it lazily initializes the first compaction point. This also avoids problems later when the first region may not be committed. Also reviewed by K. Barrett.
Reviewed-by: brutisso
8048088: Conservative maximum heap alignment should take vm_allocation_granularity into account
Summary: Also consider os::vm_allocation_granularity in the calculation.
Reviewed-by: brutisso