Fix _mm256_shuffle_ps mask! Example, for mask=203, Instead of:

  <i32 3, i32 2, i32 8, i32 11, i32 3, i32 6, i32 12, i32 15>
generate:
  <i32 3, i32 2, i32 8, i32 11, i32 7, i32 6, i32 12, i32 15>

llvm-svn: 138411