cmd/cue: add test case for modrename with a bad module

This will be fixed in the next CL.

Signed-off-by: Roger Peppe <[email protected]>
Change-Id: I86c18f260aef15a8d7cd6c7ea7b1371aa3e265f7
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1216868
TryBot-Result: CUEcueckoo <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>
Reviewed-by: Daniel Martí <[email protected]>

Author: rogpeppe

cmd/cue/cmd/testdata/script/modrename_badmodule.txtar

@@ -0,0 +1,8 @@
+# Test that we see an error when the module cannot be loaded
+
+# TODO this should be an error
+exec cue mod rename other.org
+
+-- cue.mod/module.cue --
+// Note: no language version
+module: "main.org"