[Bug c/82922] Request: add -Wstrict-prototypes to -Wextra as K&R style is obsolescent

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82922

--- Comment #7 from Martin Sebor <msebor at gcc dot gnu.org> ---
I posted a GCC 9 patch here:
  https://gcc.gnu.org/ml/gcc-patches/2018-06/msg00675.html

It adds -Wstrict-prototypes to -Wall.  Unfortunately, it got derailed by (IMO
unsubstantiated) concerns about the impact on some poorly written configure
tests.  I'll see if I can find the time to adjust the patch to enable the
option only with -Wextra and convince the powers that be to accept it into GCC
9.