I've grabbed the missing routines from musl libc (and culled some parts of the Lua standard library for the sake of reducing the number of requirements, e.g. io

I've grabbed the missing routines from musl libc (and culled some parts of the Lua standard library for the sake of reducing the number of requirements, e.g. io.*), and used venerable Doug Lea's malloc for memory allocations. The stock Lua 5.1 has the least number of dependencies, so I picked it - the idea is to practice and then to eventually have LuaJIT run on bare metal.