This issue was initially reported here:eslint/typescript-eslint-parser#579

What version of TypeScript are you using?
3.1.3

What version oftypescript-eslint-parser are you using?
21.0.2

What code were you trying to parse?

importReactfrom'react';declare global{interfaceGlobal{__r:typeofReact;}}// To complement `global.__r = React;`

What did you expect to happen?
No lint errors

What happened?

6:18 error 'React' is not defined no-undef

typescript-eslint-parser/analyze-scope.js:Referencer.visitGlobalAugmentation seems to replace the current scope with the global one, which makes accessingReact in the above example
incorrectly say it's not defined.

@mysticatea (via#540): what case does visitGlobalAugmentation solve?