[bindgen] Include Version in the export name if needed

[jsturtevant]

When exporting multiple versions of the same package the version name needs to be included.

Before this change the generator would produce:

pub fn test_dep_test(&self) -> &exports::test::dep0_1_0::test::Test { &self.interface1 } 
pub fn test_dep_test(&self) -> &exports::test::dep0_2_0::test::Test { &self.interface2 }

now it will produce:

pub fn test_dep_0_1_0_test(&self) -> &exports::test::dep0_1_0::test::Test { &self.interface1 } 
pub fn test_dep_0_2_0_test(&self) -> &exports::test::dep0_2_0::test::Test { &self.interface2 }

Found in https://github.com/bytecodealliance/wit-bindgen/pull/787/files#r1416724258
Discussed in https://bytecodealliance.zulipchat.com/#narrow/stream/327223-wit-bindgen/topic/Host.20Exports.20across.20versions

[jsturtevant]

This has the side affect of creating crazy names like the following and is why CI is failing (local tests worked on generation project)

proxy
                .wasi_http_0_2_0_rc_2023_12_05_incoming_handler()
                .call_handle(store, req, out)

Since this is not super common (at least so far), if there is only one export for that pacakage/interface combination then don't include the version (same as it is today). For situations where there are two exports and the long name isn't desired we could have an override like:

// can provide overrides
wasmtime::component::bindgen!({
exports: {
        "test:dep/test@0.1.0": "test_dep_test",
        "test:dep/test@0.2.0": "test_dep_test_02",
    }

[alexcrichton]

Thanks! Could you clarify though? You mention that CI is failing but it looks passing here. This additionally implements what I would expect which is that versions are dropped unless they're required, so this looks good to go to me modulo a suggestion below to use a preexisting helper, but I wanted to confirm I wasn't missing anything.

[jsturtevant]

Sorry for the confusion, you are not missing anything. The ci is passing now. I made that comment before I fixed it with the latest commit, which drops the version if there is only one.

This additionally implements what I would expect which is that versions are dropped unless they're required,

Should this be applied across all bindgen projects? I recently made a change to the c# wit-bindgen to add the version to the namespaces bytecodealliance/wit-bindgen#781. It adds the version if present.

[alexcrichton]

Personally at least, yes, I think all bindings generators should drop versions unless there's an ambiguity. Helps promotes the use of versions I think without causing all the generated bindings to look terrible ideally. I haven't gotten around to implementing this much elsewhere other than the Wasmtime host and Rust guest generators though.