[runtime] Add fast-paths for common conversion methods

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index e3b47427e38251435c4d4ab36f7498d7ec34029b..ece40a5e38b12e20d0ce83f655cf97cea046533c 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -1102,6 +1102,13 @@ MaybeHandle<Name> Object::ToName(Isolate* isolate, Handle<Object> input) {
 }
 
 // static
+MaybeHandle<Object> Object::ToPropertyKey(Isolate* isolate,
+                                          Handle<Object> value) {
+  if (value->IsSmi() || HeapObject::cast(*value)->IsName()) return value;
+  return ConvertToPropertyKey(isolate, value);
+}
+
+// static
 MaybeHandle<Object> Object::ToPrimitive(Handle<Object> input,
                                         ToPrimitiveHint hint) {
   if (input->IsPrimitive()) return input;
@@ -1138,6 +1145,22 @@ MaybeHandle<String> Object::ToString(Isolate* isolate, Handle<Object> input) {
   return ConvertToString(isolate, input);
 }
 
+// static
+MaybeHandle<Object> Object::ToLength(Isolate* isolate, Handle<Object> input) {
+  if (input->IsSmi()) {
+    int value = std::max(Smi::cast(*input)->value(), 0);
+    return handle(Smi::FromInt(value), isolate);
+  }
+  return ConvertToLength(isolate, input);
+}
+
+// static
+MaybeHandle<Object> Object::ToIndex(Isolate* isolate, Handle<Object> input,
+                                    MessageTemplate::Template error_index) {
+  if (input->IsSmi() && Smi::cast(*input)->value() >= 0) return input;
+  return ConvertToIndex(isolate, input, error_index);
+}
+
 bool Object::HasSpecificClassOf(String* name) {
   return this->IsJSObject() && (JSObject::cast(this)->class_name() == name);
 }