[X86] Add more of the icc unaligned load/store to/from 128 bit vector intrinsics

Summary:
This patch adds
_mm_loadu_si32
_mm_loadu_si16
_mm_storeu_si64
_mm_storeu_si32
_mm_storeu_si16

We already had _mm_load_si64.

Reviewers: spatel, RKSimon

Reviewed By: RKSimon

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D52665

llvm-svn: 343388