Some platforms use lib64 instead of lib

[davidgfnet]

On my fedora f27 system, I get these libs built:
libtransistor/dist/lib64/libc++abi.a
libtransistor/dist/lib64/libc++.a
libtransistor/dist/lib/libc++abi.a
libtransistor/dist/lib/libc++.a

The files under /lib/ are empty whereas the real meat is in the lib64 ones. This is AFAIK cause Fedora in general uses /usr/lib for 32 bits stuff and /usr/lib64 for 64 bit stuff. This has caused me headache in the past while coming up with "install" rules in Makefiles and I'm unsure on how most packages figure the right path out.
That manifests in a weird error, instead of complaining about linking against an empty .a file (which might be even legal who knows!) it of course complains at linking time about missing symbols related to exceptions and C++ crap.
I just moved the files after libtransistor-base stuff is built and seems to work so far to a successful built, but would be nice to fix this issue so Fedora works out of the box.
Just thinking about this I still dont get why they end un in lib64, is it maybe that fedora supports multilib for aarch32/64 so 64 bit libs land in /lib64/ similarly to intel arches?