[tlbuild] new clisp/libffcall/libsigsegv for testing

[Akira Kakuto]

Dear Bruno,

>> Thank you for the patch. I'll be including it in the next prerelease.

>  This "next prerelease" is at
>   https://haible.de/bruno/gnu/clisp-2.49.51.tar.bz2

I have succeeded to build on Windows with the old mingw32.
Many thanks.

Best,
Akira