[builtins] Make Math.ceil, Math.trunc and Math.round optimizable.

src/compiler/simplified-operator-reducer.cc

Index: src/compiler/simplified-operator-reducer.cc
diff --git a/src/compiler/simplified-operator-reducer.cc b/src/compiler/simplified-operator-reducer.cc
index 48aca9729e0393b1a9ba8db7a07c52b75581a841..012004a8af6c1c895fd680c589501cd19c300bb1 100644
--- a/src/compiler/simplified-operator-reducer.cc
+++ b/src/compiler/simplified-operator-reducer.cc
@@ -89,8 +89,17 @@ Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
       if (m.HasValue()) return ReplaceNumber(FastUI2D(m.Value()));
       break;
     }
+    case IrOpcode::kNumberCeil:
     case IrOpcode::kNumberFloor:
-      return ReduceNumberFloor(node);
+    case IrOpcode::kNumberRound:
+    case IrOpcode::kNumberTrunc: {
+      Node* const input = NodeProperties::GetValueInput(node, 0);
+      Type* const input_type = NodeProperties::GetType(input);
+      if (input_type->Is(type_cache_.kIntegerOrMinusZeroOrNaN)) {
+        return Replace(input);
+      }
+      break;
+    }
     case IrOpcode::kReferenceEqual:
       return ReduceReferenceEqual(node);
     default:
@@ -99,16 +108,6 @@ Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
   return NoChange();
 }
 
-Reduction SimplifiedOperatorReducer::ReduceNumberFloor(Node* node) {
-  DCHECK_EQ(IrOpcode::kNumberFloor, node->opcode());
-  Node* const input = NodeProperties::GetValueInput(node, 0);
-  Type* const input_type = NodeProperties::GetType(input);
-  if (input_type->Is(type_cache_.kIntegerOrMinusZeroOrNaN)) {
-    return Replace(input);
-  }
-  return NoChange();
-}
-
 Reduction SimplifiedOperatorReducer::ReduceReferenceEqual(Node* node) {
   DCHECK_EQ(IrOpcode::kReferenceEqual, node->opcode());
   Node* const left = NodeProperties::GetValueInput(node, 0);