const internal/types/errors.UnsupportedFeature

4 uses

	internal/types/errors (current package)
		code_string.go#L142: 	_ = x[UnsupportedFeature-135]
		codes.go#L1321: 	UnsupportedFeature

	go/types
		decl.go#L587: 				check.error(tdecl, UnsupportedFeature, "generic type alias requires GODEBUG=gotypesalias=1 or unset")
		errors.go#L255: 	err := check.newError(UnsupportedFeature)