If you're looking for musl cross-compilers, they're here.
This page is a simple collection of musl-related resources by Gregor Richards. He maintains the Snowflake Linux/musl distribution and its associated patches to NetBSD pkgsrc, as well as the musl-cross cross compilers.
Archived pkgsrc build results are stored here. Prebuilt musl cross compilers are here.
(Gregor cannot decide whether “cross compiler” is hyphenated or not)