AST to AST JIT Backend

[James Lu]

I have an idea, one way we can get faster compiles for Dlang is 
by compiling to an existing JITted language, which could be 
easier to build a proof of concept for than a full optimizing JIT 
compiler.

Perhaps we could compile Dlang to Lua, targeting LuaJIT or 
JavaScript, targeting V8.

I personally know to write highly performant JavaScript very 
well. Combined with Dlang's natural type information, it could 
result in fast machine code, fast. Backends for the Nim language 
tend to output poor (slow) JavaScript code.

In an earlier thread, I showed that the V8 JavaScript engine 
could generate decent quality machine code much faster than LLVM 
D Compiler.