rpmalloc is currently very aggressively configured which causes
significant reductions in resident memory over jemalloc.
In Bayonetta's title screen it went from 963MB down to 834MB resident.
Still creates a copy of FEXInterpreter from FEX for downstream projects
to have some time to get off the old name. Creating a symlink is kind of
a pain in cmake so just doing an install copy is easy.
Ryan Houdek