Simplify buildVectorSupportsSourceMods()

Author: chrisjbris

llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp

@@ -726,12 +726,6 @@ static bool buildVectorSupportsSourceMods(const SDNode *N) {
   if (N->getValueType(0) != MVT::v2f32)
     return true;
 
-  assert(!N->use_empty());
-
-  for (const SDNode *U : N->users())
-    if (U->getOpcode() != ISD::BITCAST)
-      return true;
-
   SDValue LHS = N->getOperand(0);
   SDValue RHS = N->getOperand(1);
   if (LHS->getOpcode() != ISD::SELECT || RHS->getOpcode() != ISD::SELECT)