Unlike other v6+ processors, cortex-m0 never supports unaligned accesses.
From the v6m ARM ARM:
"A3.2 Alignment support: ARMv6-M always generates a fault when an unaligned
access occurs."
rdar://16491560
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205452 91177308-0d34-0410-b5e6-96231b3b80d8