[X86] Update PADDSW/PSUBSW intrinsic usage with generic saturated intrinsics.
[X86] Update PADDSW/PSUBSW intrinsic usage with generic saturated intrinsics.

As discussed on D55894, this makes no difference to the actual test.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@349742 91177308-0d34-0410-b5e6-96231b3b80d8

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