Remove bad build_vector hasSourceMods() implementation.

Author: chrisjbris

llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp

@@ -726,18 +726,6 @@ static bool selectSupportsSourceMods(const SDNode *N) {
   return N->getValueType(0) == MVT::f32;
 }
 
-LLVM_READONLY
-static bool buildVectorSupportsSourceMods(const SDNode *N) {
-  if (N->getValueType(0) != MVT::v2f32)
-    return true;
-
-  if (N->getOperand(0)->getOpcode() != ISD::SELECT ||
-      N->getOperand(1)->getOpcode() != ISD::SELECT)
-    return true;
-
-  return false;
-}
-
 // Most FP instructions support source modifiers, but this could be refined
 // slightly.
 LLVM_READONLY
@@ -771,8 +759,6 @@ static bool hasSourceMods(const SDNode *N) {
       return true;
     }
   }
-  case ISD::BUILD_VECTOR:
-    return buildVectorSupportsSourceMods(N);
   case ISD::SELECT:
     return selectSupportsSourceMods(N);
   default: