Genera support

Symbolics Genera is still alive and under active development. I recently released Genera 9.0, the first major release in almost 30 years, running in the Virtual Lisp Machine (VLM) on Intel and ARM Linux and macOS systems. (Unfortunately, licensing is still being worked out.)

Genera 9.0 includes ASDF as an optional module and Quicklisp will also be available once my pull requests are merged.

I made the following changes to allow running CL-BENCH on Genera.

• Refuse to load CL-BENCH on versions of Genera older than 9.0.
• Add the extensions for Genera's compiled files (.bin, .ibin, and .vbin) to the .gitignore
• Remove an incorrect package name from the attribute list of files/deflate.lisp
• Disable several benchmarks on Genera
  • Genera's compiler doesn't implement tail recursion optimization which causes walk-list/mess to overflow the stack and, eventually, crash Genera
  • ackermann is disabled for the lack of tail recursion as well
  • Genera runs out of address space running string-concat -- (Actually, that's an oversimplification of the problem but it's good enough for this merge request.)