https://gcc.gnu.org/bugzilla/show_bug.cgi?id=32667
--- Comment #50 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- Qualifiers on function parameter types do not affect type compatibility or composite type (see 6.7.6.3#14). I think they're only actually of significance in the definition; in a declaration they effectively serve as documentation.
