r110953 and --enable-gcc-warnings

[Dmitry Antipov]

Since r110953 I see:

trunk/src/dispnew.c: In function ‘Fframe_or_buffer_changed_p’:
trunk/src/dispnew.c:6049:7: error: assuming signed overflow does not occur when 
simplifying conditional to constant [-Werror=strict-overflow]
trunk/src/dispnew.c:6058:7: error: assuming signed overflow does not occur when 
simplifying conditional to constant [-Werror=strict-overflow]
trunk/src/dispnew.c:6060:7: error: assuming signed overflow does not occur when 
simplifying conditional to constant [-Werror=strict-overflow]
trunk/src/dispnew.c:6062:7: error: assuming signed overflow does not occur when 
simplifying conditional to constant [-Werror=strict-overflow]
trunk/src/dispnew.c:6066:3: error: assuming signed overflow does not occur when 
simplifying conditional to constant [-Werror=strict-overflow]
cc1: all warnings being treated as errors

Configuration is:

../configure --prefix=/not/exists --with-x-toolkit=gtk3 --enable-gcc-warnings 
--enable-check-lisp-object-type --enable-checking

Stock GCC 4.7.2 under x86_64 Fedora 17.

Dmitry