[Bug middle-end/63510] Wrong line number in Wstrict-overflow message

[gang.chen.5i5j at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63510

--- Comment #3 from Chen Gang <gang.chen.5i5j at gmail dot com> ---
It still exists in gcc version 5.0.0 20141109 (experimental) (GCC), I shall try
to solve it.

Hope I can finish within 2 months.