[RFC]: c99 compiled world

hi

I tried to compile world in  C99 (in fact gnu99) gcc mode. It
compiles correctly with two trivial exceptions (in sendmail
and opensolaris) which are going to get fixed soon.

So, what is your opinion on turning C99 (gnu99) on default in
-current to exposure it to some testing. can you see some drawbacks?

thnx for your opinions

roman