AMDGPU/GlobalISel: Fix assert on multi-return side effect intrinsics

llvm.amdgcn.else hits this.

llvm-svn: 371812
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
index c1c515a..23ca49b 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
@@ -731,7 +731,7 @@
   MachineFunction *MF = BB->getParent();
   MachineRegisterInfo &MRI = MF->getRegInfo();
 
-  unsigned IntrinsicID = I.getOperand(0).getIntrinsicID();
+  unsigned IntrinsicID = I.getIntrinsicID();
   switch (IntrinsicID) {
   case Intrinsic::amdgcn_exp: {
     int64_t Tgt = getConstant(MRI.getVRegDef(I.getOperand(1).getReg()));