c++/9259: [2003-04-07] Calling a non-qualified member function within a sizeof() expression leads to "invalid use of undefined type"

[Giovanni Bajo]

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=9259

It was not noted in this PR, but to fix the bug it's sufficient to qualify
the function call (sizeof(S::check()) instead of sizeof(check())), which
means that the bug happens only in non-qualified member function calls
within sizeof expressions.

Giovanni Bajo