require-atomic-updates isn't consistent between locals and params

[darthwalsh]

Tell us about your environment

• ESLint Version: 6.0.1
• Node Version: 10.15.3
• npm Version: 6.4.1

What parser (default, Babel-ESLint, etc.) are you using?
default

Please show your full configuration:
require-atomic-updates: error

Configuration

env:
  browser: true
  es6: true
globals:
  Atomics: readonly
  SharedArrayBuffer: readonly
parserOptions:
  ecmaVersion: 2018
rules:
  require-atomic-updates: error

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.

Demo online

safe = async p => {
  const player = p
  player.money += await player.calculateIncome(); // no error
}

unsafe = async player => {
  player.money += await player.calculateIncome(); // Possible race condition
}

node_modules/.bin/eslint a.js

What did you expect to happen?
I'd prefer neither line to cause an error, but for consistency both lines should at least have the same behavior.

#10655 specified that local variables should be excluded. Function parameters have the same scope as local variables in the function. As far as I can reason as long as the local or param isn't captured by a closure, there's no reason to treat them differently.

If this was changed, I suspect it would also fix #11899

What actually happened? Please include the actual, raw output from ESLint.

~/code/blah$ node_modules/.bin/eslint a.js

~/code/blah/a.js
  7:3  error  Possible race condition: `player.money` might be reassigned based on an outdated value of `player.money`  require-atomic-updates

✖ 1 problem (1 error, 0 warnings)

Are you willing to submit a pull request to fix this bug?
My employer hasn't pre-approved your CLA, and there's probably no business justification for fixing this

[mysticatea]

Thank you for your report.

I think this is a duplicate of #11899. Please track that issue.