Fix the computation of the size of the stack maps region.

In art::StackMapStream::ComputeStackMapSize, compute the
size of a CodeInfo's stack maps region using the stack
mask size, not the maximum element of the stack mask.
Also, rename this method as
art::StackMapStream::ComputeStackMapsSize to make it clear
it that it covers all the stack maps of the CodeInfo item,
not just one stack map.

Change-Id: Icad21946dbca6e1ade2b82c9c2c535fdfed110a9
2 files changed