babel-runtime and babel-polyfill should have option to not polyfill ES5 functionality (T7517)

[babel-bot]

Issue originally made by @taion

Bug information

• Babel version: 6.11.4
• Node version: 6.3.1
• npm version: 3.10.3

Options

.babelrc:

{
  "plugins": ["transform-runtime"]
}

Input code

Object.create(a);

Description

The output code here is:

import _Object$create from "babel-runtime/core-js/object/create";
_Object$create(a);

babel-polyfill pulls in this polyfill as well, but it's harder to demonstrate.

Given that Babel assumes that code will run in an ES5 environment, it seems incorrect to ship polyfills for ES5 functionality by default.

This also applies somewhat to e.g. the much more commonly used Object.keys, where the difference between ES5 and ES2015 is relatively minor and unlikely to come up in practice.

[babel-bot]

Comment originally made by @taion

This is veering into feature request territory, but I think:

• Babel polyfills should never include strict ES5 functionality like Object.create
• Babel polyfills should expose a "loose" mode (option for babel-plugin-transform-runtime, maybe babel-polyfill/loose) that pragmatically omits polyfills for functionality like Object.keys where the specific ES2015 semantics are usually unnecessary

[hzoo]

lets move this into #3934