Message 361843 - Python tracker

Start of this issue:

"Current Makefile.pre.in contains paths like $(exec_prefix)/lib, which bad especially for mixed 32-bit and 64-bit systems, where 64-bit things should go to /lib64."

That's a duplicate of bpo-1294959. This issue discuss also modifying distutils but there is no clear plan on how it should behave or not. My PR 18381 of bpo-1294959 updates sysconfig and distutils to support $prefix/$python_libdir/ path.