WASM -> x64 as in a full WASM AOT compiler? Don't those already exist? What's the benefit to making one specifically for LFortran? Unless I'm misunderstanding
Yes, we could make the WASM->x64 standalone. The main motivation is speed of compilation. We do not do any optimizations, but we want to generate the x64 binary as quickly as possible, with the idea that it would be used in Debug mode, for development. Then for Release mode you would use LLVM, which is slow to compile, but good runtime performance. And since we already have ASR->WASM backend (used for example at https://dev.lfortran.org/), maintaining WASM->x64 is much simpler than ASR->x64 directly.
I think the question was why maintain your own WASM->x64 at all though? Couldn't you just run an existing WASM->x64 tool (using -O0 or equivalent if the goal is quick compilation for debug mode)?