Special files we keep or toss in a package on *NIX

Which of the following do we keep or toss?
1. `*.pc` pkg-config files (placed in `$PREFIX/lib/pkgconfig/...`. useful for compile options to use with a dependency)
2. `*.la` libtool files (placed in `$PREFIX/lib/`. useful for figuring out where libraries live).
3. `*.m4` m4 files (clear value during build. some are installed in `$PREFIX/share/aclocal`. Why? 😕)
4. `*.1`, `*.2`, etc. man files (placed in `$PREFIX/share/man/...`. used by `man`, which we don't use).

My vote is keep 1 and 2, but drop 3 and 4. I know cases where 1 has been helpful ( https://github.com/conda-forge/ncurses-feedstock/pull/11 ). There are cases where 2 is important right now I'm debugging one.

I don't really understand the value of 3. So, drop? Maybe someone with more Linux knowledge (@ocefpaf?) could help us here.

As we can't use 4 now and it can take up some space, my vote is drop.

If we follow this route, we can just always add `rm -rf $PREFIX/share/aclocal` and `rm -rf $PREFIX/share/man`. Though honestly that directory more often than not includes junk so we should be able to always do `rm -rf $PREFIX/share`.