compiler: disallow most types in //go:wasmimport

This is for compatibility with upstream Go.
See https://github.com/golang/go/issues/59149 for more context.

compiler/testdata/pragma.go

@@ -62,10 +62,6 @@ func exportedFunctionInSection() {
 //go:wasmimport modulename import1
 func declaredImport()
 
-//go:wasmimport modulename import2
-func definedImport() {
-}
-
 // This function should not: it's only a declaration and not a definition.
 //
 //go:section .special_function_section