Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

Affected core subsystem(s)

repl, url, tools

Prehistory

In #14021, I've committed something like this by an oversight:

const assert = require('assert');
if (!common.hasCrypto)
  common.skip('missing crypto');

const common = require('../common');

assert and common lines was erroneously swapped. All tests have failed except linter.

ESLint has a rule for these cases: http://eslint.org/docs/rules/no-use-before-define

It has 3 options for classes, functions, and variables. I've left the class function on (defaults) as its violation is noted to be potentially dangerous. I've set the function option off as this is considered safe due to hoisting. And I've set the variable option off as we have many cases with cross-references from callbacks which are rather difficult to refactor. But with this option off, the rule will still check cases inside the same scope, like my above-mentioned error.

The first commit fixes 2 fragments in libs, the second one applies the rule.