Sparc*: Prevent GHC from doing unaligned accesses
Sparc*: Prevent GHC from doing unaligned accesses

This is specifically for the C backend on Sparc64 (which has
no native backend) but is also required for Sparc when building
un-registerised.

Bug reported via Debian (patch included):

    https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=842780

Test Plan: validate

Reviewers: hvr, Phyx, bgamari, austin, simonmar

Reviewed By: Phyx

Subscribers: jrtc27, thomie

Differential Revision: https://phabricator.haskell.org/D2661

GHC Trac Issues: #12793

ezyang/ghc,sdiehl/ghc,mettekou/ghc,olsner/ghc,olsner/ghc,ezyang/ghc,ezyang/ghc,olsner/ghc,olsner/ghc,ezyang/ghc,sdiehl/ghc,shlevy/ghc,sdiehl/ghc,shlevy/ghc,sdiehl/ghc,sdiehl/ghc,mettekou/ghc,shlevy/ghc,shlevy/ghc,mettekou/ghc,mettekou/ghc,shlevy/ghc,olsner/ghc,shlevy/ghc,olsner/ghc,mettekou/ghc,mettekou/ghc,olsner/ghc,mettekou/ghc,sdiehl/ghc,ezyang/ghc,sdiehl/ghc,ezyang/ghc,shlevy/ghc,ezyang/ghc