moonjit-2.1.2-2.1

- Obsolete/provide lua51-luajit as it was the old luajit name

- Fork of luajit with more active upstream
- Version 2.1.2 building on top of 2.1.0-beta3 with following goodies:
  * fix for CVE-2019-19391
  * Support for ppc64 ppc64le s390 s390x
- Still carry the patch luajit-lua-versioned.patch to mark it as
  compatible with lua 5.1, future 2.2 release should contain
  support for 5.2 and 5.3 release of LUA