tweak to b37ad3c; install libstp_stub.so when STP_STUB=1

[jcumming]

Hello,

I'm updating the NixOS metadata to use bsc 103357f.

To get everything running, I needed to make a small patch to src/vendor/stp/Makefile to copy libstp_stub.so to inst/lib/SAT.

It would be great to be able to upstream this patch so we don't need to carry it anymore in the nixpkgs repo. The rest of the nix metadata changes are in jcumming/nixpkgs@442d1ae.

There are still 13 failures in bsc-testsuite (without SystemC), but those mostly seem to be NixOS-isms (like /bin/echo not existing).

[quark17]

This is a good catch, thanks. I've been meaning to test building with STP_STUB=1 on macOS, to see whether a similar change is needed in that case, too.

My feeling is that we might want to do one of two things: (A) Remove SNAME and install lib/*, so that the makefile installs whatever files were created, or (B) rename SNAME to INSTALLNAMES and make sure that we populate it properly with the names for all combinations of OSes and stub or no stub.

Also, if you've discovered that there are tools that the testsuite requires (such as echo) that are not mentioned in the README but are worth documenting, feel free to contribute that.