T11758 testcase help needed

Hi, all! I was working on #11758, which is about dropping binutils<2.17 hack, and while it was relatively easy to remove the hack itself, I'm not sure how to add a test case for it. As I understand, after removing the aforementioned hack, native codegen now shouldn't generate sign extension. So my question is how to test it? Should it be Cmm file that will be tested with `compile_cmp_asm` like memcpy in "codeGen/should_gen_asm/memcpy.cmm"? Or should I stick to the Haskell test? Thanks, Alex Dzyoba