[Bug c++/120449] g++ -Wtype-limits without -P doesn't warn on unsigned compare to zero

[zmajeed at sbcglobal dot net via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120449

--- Comment #2 from Zartaj Majeed <zmajeed at sbcglobal dot net> ---
Is -Wsystem-headers a side-effect of -P? Because system headers cannot be
recognized if line numbers are suppressed?