Add support for compiler-rt

Would like to start a discussion about the best way to support compiler-rt in Numba. For background there is a outstanding feature request:

Additionally I have made progress on that issue by creating a pull request in llvmlite that provides suport for the addArchive method provided by LLVM:

There was discussion at the most recent Numba development meeting on February 7th:

One answer I can provide from the development meeting is that compiler-rt is only available (hardcoded in the cmake build process) as a static library

And finally compiler-rt is available as a separate conda package:

My question is should we create a separate wheel for compiler-rt or package it with the llvmlite wheel?

From out-of-band discussion with @testhound, we think the most doable way is to copy into the objectfiles from compiler-rt and package those as package-data along llvmlite.

@sklam if we can copy the object files why can’t we copy the static archive and provide it as package-data?

@testhound, copying the static archive works too.