[Bug c/53232] No warning for main() without a return statement with -std=c99

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53232

--- Comment #12 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Because GCC is primarily a compiler, not a linter for portability problems.