[HSA-670 Fix] Fix bugs with Cvt in 32-bit release build
[HSA-646 Fix] Fix translation of BrigInstSourceType operand and
              add brig_reader_test for popcount_u32_b64
[HSA-647 Fix] Add brig_reader_test for firstbit_u32_u64
[HSA-648 Fix] Add brig_reader_test for Lastbit_u32_u64
[HSA-649 Fix] Add runtime test for Pack()
              Fix validatePack()