@babel/preset-env: `DEBUG` option

Using targets:
{
  "chrome": "71"
}

Using modules transform: auto

Using plugins:
  syntax-async-generators { "chrome":"71" }
  syntax-object-rest-spread { "chrome":"71" }
  syntax-json-strings { "chrome":"71" }
  syntax-optional-catch-binding { "chrome":"71" }

Using polyfills with `usage` option:

[<CWD>/src/in.js] Added following core-js polyfill:
  web.dom.iterable { "chrome":"71" }

[<CWD>/src/in2.js] Added following core-js polyfill:
  web.dom.iterable { "chrome":"71" }
Successfully compiled 2 files with Babel.