[PATCH] Optimize shufflevector that copies an i64/f64 and zeros the rest.

[Elena Demikhovsky]

================
Comment at: lib/Target/X86/X86ISelLowering.cpp:7517
@@ -7514,3 +7516,3 @@
       return DAG.getNode(ISD::BITCAST, dl, VT, NewOp);
-  } else if ((VT == MVT::v4i32 ||
-             (VT == MVT::v4f32 && Subtarget->hasSSE2()))) {
+  } else if (VT == MVT::v4i32 ||
+             (VT.is128BitVector() && Subtarget->hasSSE2())) {
----------------
v4i32 is covered by 128bitVector.
All other LGTM

http://reviews.llvm.org/D3518