This is a reland of part of
https://chromium-review.googlesource.com/c/v8/v8/+/1397664.

It drops the explicit fni_.Infer() call after parsing arrow functions. We'll
want to avoid inferring if the arrow function is an argument to a function
call.

It also avoids adding the single argument of "name => " to the inferred name.

Bug: chromium:916975
Change-Id: I96a934408113483d73eba14073fe21e8cfe2ada6
Reviewed-on: https://chromium-review.googlesource.com/c/1397665
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58613}