wasm/hello — Rail to WebAssembly

The same Rail source compiles to ARM64 macOS, ARM64 Linux, x86_64 Linux and WASM. Here's the smallest WASM target.

Source (examples/wasm/hello.rail):

main =
  let _ = print "Hello from Rail!"
  let _ = print "Running as WebAssembly."
  0

Build (compile-only — does not execute on host):

./rail_native wasm examples/wasm/hello.rail

Output:

Compiling examples/wasm/hello.rail to WASM...
  WAT: 51277 bytes
  wat2wasm: OK
  Binary: /tmp/rail_out.wasm

The driver emits WAT (WebAssembly text), then runs wat2wasm to produce the binary at /tmp/rail_out.wasm. Drop that file into the playground at https://ledatic.org or load it in any WASM runtime that supplies the small env import set (print, etc.).