>This change to pragma(mangle) should be in separate pull (along with the code deletion in the change to testsuite).

I was planned to create separate pull.

>It would be a strong suggestion to disallow non-printable characters in mangling.

And we returns to question about validation of mangle :o) I sure that if we should validate mangle, we should do it _not_ in frontend.

>I can't think of any valid case for this. :)

Please: compressed symbols on OMF format. They can contain any sequence of bytes (include non-printable). And I not sure, but borland linkers (which also use OMF) can use another compression algorithm then dmc.