JITs are more-or-less portable now. Lua's, like most, probably came originally from some Javascript's. But of course they all trace back conceptually to HotSpot in the '90s. Even Guile Scheme is JITted now, though it probably shares no code with the others.
The term "JIT" is getting abused lately to describe what happens to users' eBPF code that runs in the Linux kernel, and Wasm that runs in browsers. In those, all types are known statically, code is compiled to a portable form offline, and transcribed to machine code before any execution, and none of the runtime instrumentation, analysis, and progressive rewriting occurs.
The term "JIT" is getting abused lately to describe what happens to users' eBPF code that runs in the Linux kernel, and Wasm that runs in browsers. In those, all types are known statically, code is compiled to a portable form offline, and transcribed to machine code before any execution, and none of the runtime instrumentation, analysis, and progressive rewriting occurs.