Rollup merge of #70133 - hermitcore:libpanic_unwind, r=nikomatsakis
Rollup merge of #70133 - hermitcore:libpanic_unwind, r=nikomatsakis

remove unused imports

patch is required to avoid compiler errors by building src/libpanic_unwind/hermit.rs

graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust