Add a few Subzero intrinsics (not the atomic ones yet).

src/IceTargetLowering.cpp

Index: src/IceTargetLowering.cpp
diff --git a/src/IceTargetLowering.cpp b/src/IceTargetLowering.cpp
index 72a3e8ce3dfe7051e0e1641ee86e6c351ec03178..877f717dea7ed9b5b6bfcf7822c4ab66c78b89d2 100644
--- a/src/IceTargetLowering.cpp
+++ b/src/IceTargetLowering.cpp
@@ -116,6 +116,9 @@ void TargetLowering::lower() {
   case Inst::Icmp:
     lowerIcmp(llvm::dyn_cast<InstIcmp>(Inst));
     break;
+  case Inst::IntrinsicCall:
+    lowerIntrinsicCall(llvm::dyn_cast<InstIntrinsicCall>(Inst));
+    break;
   case Inst::Load:
     lowerLoad(llvm::dyn_cast<InstLoad>(Inst));
     break;