Do not use Object.getOwnPropertyDescriptors when target is set to anything lower than es2017

[cyan-2048]

related issue #2631

Object.getOwnPropertyDescriptors is an es2017 static method (source: 1, 2)

However esbuild uses this method even if you set the target to es6.

hyrious.me/esbuild-repl/?version=0.25.0

Input:

const a = {a: "a"};
const b = {b: "b"}
const c = {...a,...b, c: "c"};

Output:

var __defProp = Object.defineProperty;
var __defProps = Object.defineProperties;
var __getOwnPropDescs = Object.getOwnPropertyDescriptors;
var __getOwnPropSymbols = Object.getOwnPropertySymbols;
var __hasOwnProp = Object.prototype.hasOwnProperty;
var __propIsEnum = Object.prototype.propertyIsEnumerable;
var __defNormalProp = (obj, key, value) => key in obj ? __defProp(obj, key, { enumerable: true, configurable: true, writable: true, value }) : obj[key] = value;
var __spreadValues = (a2, b2) => {
  for (var prop in b2 || (b2 = {}))
    if (__hasOwnProp.call(b2, prop))
      __defNormalProp(a2, prop, b2[prop]);
  if (__getOwnPropSymbols)
    for (var prop of __getOwnPropSymbols(b2)) {
      if (__propIsEnum.call(b2, prop))
        __defNormalProp(a2, prop, b2[prop]);
    }
  return a2;
};
var __spreadProps = (a2, b2) => __defProps(a2, __getOwnPropDescs(b2));
const a = { a: "a" };
const b = { b: "b" };
const c = __spreadProps(__spreadValues(__spreadValues({}, a), b), { c: "c" });

[cyan-2048]

this has bothered me for a while actually, since you can't even polyfill it by importing npm packages if building with esbuild/vite, because these runtime functions are added before anything else. adding a banner is unfavorable as this runtime function is not always present in the chunked file.

as a result, I have resorted to creating a separate file for my polyfills, and also building it with esbuild separately.