Michal Terepeta authored Nov 07, 2018 and Ben Gamari committed Nov 07, 2018

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 <michal.terepeta@gmail.com>

Test Plan: manually run tests with WAY=llvm

Reviewers: bgamari, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, carter

GHC Trac Issues: #15864

Differential Revision: https://phabricator.haskell.org/D5304