[pshinter] Fix mask merging.

We forgot to update the number of bits when merging a larger mask
into a smaller one.  This fix might have rendering effects.

* src/pshinter/pshrec.c (ps_mask_table_merge): Inherit the number
of bits from a larger mask. There is no need to zero unused bits,
already zeroed during allocation.
(ps_mask_clear_bit): Removed.
(ps_mask_ensure): Minor.
1 file changed