[PATCH] MC: handle .cfi_startproc simple

Really sorry I missed this. Just found it looking for something else
in my inbox.

I think we should support this but
* We should still err on other identifiers ".cfi_startport bar" is invalid.
* If I read the gas documentation correctly, the effect of "simple" is
to skip the initial cfi instructions. We should test if that is the
case and implement it too. Accepting and ignoring "simple" is not very
user friendly.

Rafael EspĂ­ndola wrote:

I think we should support this but
[...]

I sent some other patches to achieve compatibility with GNU as, but
they weren't well received: it doesn't look like the community cares.
If you're really interested in taking this forward, please give me
hints about why my original patch breaks tests.