Auto merge of #117321 - chenyukang:yukang-fix-117142, r=petrochenkov

Fix unused_parens issue when cast is followed LT

Fixes #117142

The original check only checks `a as (i32) < 0`, this fix extends it to handle `b + a as (i32) < 0`.

A better way is maybe we suggest `(a as i32) < 0` instead of suppressing the warning, maybe following PR could improve it.

Author: bors