Rollup merge of #59468 - mati865:musl_toolchain, r=pnkfelix
Rollup merge of #59468 - mati865:musl_toolchain, r=pnkfelix

musl: build toolchain libs with -fPIC

Fixes https://github.com/rust-lang/rust/issues/59411

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