link rust staticlib into freestanding shared library
While this tool can be used to create a freestanding C dynamic shared object dso using musl toolchain, it is not quite useful because musl and glibc thread and TLS implementation are totally different, so most certainly using the produced dso would end up crash your program, unless the program is linked against the same musl libc as well.
when build the dso, select rust crate-type to staticlib to produce a .a file, then run rust-staticlib-linker to generate the final dso:
USAGE:
rust-staticlib-linker [OPTIONS] --export <export>... --output <output> --staticlib <STATICLIB>