Tell us about your environment

• ESLint Version: 6.7.0
• Node Version: 12

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

Please show your full configuration:

{
  rules: {
    camelcase: ['error', {
      "properties": "never",
      "ignoreDestructuring": true
    }],
  },
}

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

Context: typescript-eslint/typescript-eslint#1686
A user of typescript-eslint received a linting error with the following code, even though it should be covered by the options above.

  const res = {a_b:123}
  const {a_b=0} = res
//       ^^^ Error Identifier 'a_b' is not in camel case

This error occurs when parsing with typescript-eslint, and not with the default parser.
Thinking this was a bug in the typescript-eslint parser, I did some digging, and it turns out that the acorn reuses the AST node in two places (i.e. the two a_b Identifiers are referentially equal).
acornjs/acorn#928

This causes the parent references to be set incorrectly, as the node's parent will be that of whichever node was traversed last.

Logging this here because:

• the rule doesn't work with the "correct" parent pointers,
• the rule will have to be updated for when the bug in acorn is fixed.