[X86][SSE] _mm_store1_ps/_mm_store1_pd should require an aligned pointer

According to the gcc headers, intel intrinsics docs and msdn codegen the _mm_store1_pd (and its _mm_store_pd1 equivalent) should use an aligned pointer - the clang headers are the only implementation I can find that assume non-aligned stores (by storing with _mm_storeu_pd).

Additionally, according to the intel intrinsics docs and msdn codegen the _mm_store1_ps (_mm_store_ps1) requires a similarly aligned pointer.

This patch raises the alignment requirements to match the other implementations by calling _mm_store_ps/_mm_store_pd instead.

I've also added the missing _mm_store_pd1 intrinsic (which maps to _mm_store1_pd like _mm_store_ps1 does to _mm_store1_ps).

As a followup I'll update the llvm fast-isel tests to match this codegen.

Differential Revision: http://reviews.llvm.org/D20617

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@271218 91177308-0d34-0410-b5e6-96231b3b80d8