ArrowFunction incorrectly introduces 'arguments' local symbol

[ajafff]

TypeScript Version: 3.2.0-dev.20181110

Search Terms: arrow arguments

Code

(() => arguments)();

Expected behavior:

There's no arguments in scope, emit error cannot find name 'arguments'.

Actual behavior:

No compiler error. Crashes at runtime.

Playground Link: https://agentcooper.github.io/typescript-play/#code/BTCUAIF4D5wQwE4HMCuBbApgOwC4GdQwg

I can send a PR if you accept this bug as I'm already looking at the relevant code.

[DanielRosenwasser]

Thanks!