Implement a feature (-vector-unaligned-mem) to allow targets to

Implement a feature (-vector-unaligned-mem) to allow targets to
ignore alignment requirements for SIMD memory operands.  This
is useful on architectures like the AMD 10h that do not trap on
unaligned references if a status bit is twiddled at startup time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93151 91177308-0d34-0410-b5e6-96231b3b80d8