This fixes two isssues:
- Using bitcast for MO_XX_Conv Arguments to a bitcast must be of the same size. We should be using trunc and zext instead.
- Using unsupported MO_*_QuotRem for LLVM The two primops MO_*_QuotRem are not supported by the LLVM backend, so we shouldn't use them for Int8#/Word8# (just as we do not use them for Int#/Word#).
Signed-off-by: Michal Terepeta <email@example.com>