fix(semantic): allow let as arrow function param in sloppy mode

[overlookmotel]

Previously semantic would produce an error for this in sloppy mode:

const f = (let) => {};

let is legal in this position, but the loop in check_binding_identifier would continue searching past the arrow function, and would hit the VariableDeclarator which produces an error.

[overlookmotel]

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• fix(semantic): disallow let as destructured catch param in sloppy mode #12306
• fix(semantic): allow let as arrow function param in sloppy mode #12305 👈 (View in Graphite)
• perf(semantic): reduce match arms in check_binding_identifier #12304
• refactor(semantic): refactor check_binding_identifier #12303
• main

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[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #12305 will not alter performance

_{Comparing 07-15-fix_semantic_allow_let_as_arrow_function_param_in_sloppy_mode (f047374) with main (b60d63b)}

Summary

✅ 34 untouched benchmarks

[overlookmotel]

I think this is right, but I only based it on observing what NodeJS does. Need to find the part of the spec that covers this and check NodeJS/V8 is right.