fix: add empty.s to fix compilation error

[jamesstocktonj1]

Description

When attempting to run unit tests whilst importing the go.bytecodealliance.org/pkg/wit/types package I get the following compilation error:

$ go test ./...
# go.bytecodealliance.org/pkg/wit/async
.../go.bytecodealliance.org/pkg@v0.2.0/wit/async/async.go:221:6: missing function body
.../go.bytecodealliance.org/pkg@v0.2.0/wit/async/async.go:224:6: missing function body
.../go.bytecodealliance.org/pkg@v0.2.0/wit/async/async.go:227:6: missing function body
.../go.bytecodealliance.org/pkg@v0.2.0/wit/async/async.go:230:6: missing function body
.../go.bytecodealliance.org/pkg@v0.2.0/wit/async/async.go:233:6: missing function body
.../go.bytecodealliance.org/pkg@v0.2.0/wit/async/async.go:236:6: missing function body
.../go.bytecodealliance.org/pkg@v0.2.0/wit/async/async.go:239:6: missing function body
FAIL    <go module> [build failed]
FAIL

wit-bindgen-go got round this issue by including a blank empty.s assembly file within each of the directories which includes a Go file that uses the //go:wasmimport directive. See here for example.

This tricks the Go compile into thinking there is an assembly implementation of the function which has been declared, and so it no longer complains about the missing function body.

After adding the following changes, unit tests run successfully without build error.

See more

• wit-bindgen Issue

[dicej]

Thanks, @jamesstocktonj1!

@asteurer any concerns about this?