Look for SSE and instructions of this form: (and x, (build_vector c1,c2,c3,c4)).

Look for SSE and instructions of this form: (and x, (build_vector c1,c2,c3,c4)).
If there exists a use of a build_vector that's the bitwise complement of the mask,
then transform the node to
(and (xor x, (build_vector -1,-1,-1,-1)), (build_vector ~c1,~c2,~c3,~c4)).

Since this transformation is only useful when 1) the given build_vector will
become a load from constpool, and 2) (and (xor x -1), y) matches to a single
instruction, I decided this is appropriate as a x86 specific transformation.
rdar://7323335

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96389 91177308-0d34-0410-b5e6-96231b3b80d8