#500 0.74-2: crosscompile ranlib is detected, but not ar

[rofl0r]

using the standard ./configure --host=i486-linux-musl, compiler and ranlib are detected to be i486-linux-musl-gcc/i486-linux-musl-ranlib, but ar is used without a prefixed triplet (e.g. you can see ar cru) in the build log. i fixed it by running make AR=i486-linux-musl-ar, overriding the configure-set default.