[turbofan] Drop the obsolete TypeGuard operator.

src/compiler/js-intrinsic-lowering.cc

Index: src/compiler/js-intrinsic-lowering.cc
diff --git a/src/compiler/js-intrinsic-lowering.cc b/src/compiler/js-intrinsic-lowering.cc
index 8d24013058a1d0f2c1bf2ef1676d1b57e921f9b1..5ccbe098b59ded0c193c6dce621880944ab332c3 100644
--- a/src/compiler/js-intrinsic-lowering.cc
+++ b/src/compiler/js-intrinsic-lowering.cc
@@ -34,10 +34,6 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
       return ReduceCreateIterResultObject(node);
     case Runtime::kInlineDeoptimizeNow:
       return ReduceDeoptimizeNow(node);
-    case Runtime::kInlineDoubleHi:
-      return ReduceDoubleHi(node);
-    case Runtime::kInlineDoubleLo:
-      return ReduceDoubleLo(node);
     case Runtime::kInlineGeneratorClose:
       return ReduceGeneratorClose(node);
     case Runtime::kInlineGeneratorGetInputOrDebugPos:
@@ -125,24 +121,6 @@ Reduction JSIntrinsicLowering::ReduceDeoptimizeNow(Node* node) {
   return Changed(node);
 }
 
-
-Reduction JSIntrinsicLowering::ReduceDoubleHi(Node* node) {
-  // Tell the compiler to assume number input.
-  Node* renamed = graph()->NewNode(simplified()->TypeGuard(Type::Number()),
-                                   node->InputAt(0), graph()->start());
-  node->ReplaceInput(0, renamed);
-  return Change(node, machine()->Float64ExtractHighWord32());
-}
-
-
-Reduction JSIntrinsicLowering::ReduceDoubleLo(Node* node) {
-  // Tell the compiler to assume number input.
-  Node* renamed = graph()->NewNode(simplified()->TypeGuard(Type::Number()),
-                                   node->InputAt(0), graph()->start());
-  node->ReplaceInput(0, renamed);
-  return Change(node, machine()->Float64ExtractLowWord32());
-}
-
 Reduction JSIntrinsicLowering::ReduceGeneratorClose(Node* node) {
   Node* const generator = NodeProperties::GetValueInput(node, 0);
   Node* const effect = NodeProperties::GetEffectInput(node);