Support component model `map<K, V>`

A while back the component model introduced `map` (https://github.com/WebAssembly/component-model/pull/554). I have a WIT interface which imports this, which I think might be the cause for the following ComponentizeJS panic:

```
thread '' (1) panicked at crates/spidermonkey-embedding-splicer/src/bindgen.rs:857:18:
internal error: entered unreachable code
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
An error occured while building the WASI component: RuntimeError: unreachable
```

https://github.com/bytecodealliance/ComponentizeJS/blob/12c2b4a25033f65047f8ec5c5fb9e3013bfc4950/crates/spidermonkey-embedding-splicer/src/bindgen.rs#L857

Start in crates/spidermonkey-embedding-splicer/src/bindgen.rs at line 857 and reproduce the panic with a WIT interface importing map. Trace the bindgen path reached by that input and use RUST_BACKTRACE=1 if needed. Done means ComponentizeJS handles the component-model map type without the unreachable-code panic.

索引モデルが issue の本文から書いたものです。