These are almost entirely identical, with these exceptions:
* lib/libc/include/csky-linux-{gnueabi,gnueabihf}
* gnu/{lib-names,stubs}.h will need manual patching for float ABI.
* lib/libc/include/{powerpc-linux-{gnueabi,gnueabihf},{powerpc64,powerpc64le}-linux-gnu}
* bits/long-double.h will need manual patching for long double ABI.