Don't use -Wpointer-arith if it produces excessive warnings

[Dmitry Timoshkov]

"Mike McCormack" <mike at codeweavers.com> wrote:

> Wine works around other problems on the build platform (eg. 
> strength-reduce bug, detected a few lines after my patch in 
> configure.ac).  I don't see how broken headers are any different from a 
> broken compiler or broken libraries, which we already detect and deal 
> with in the configure script.

Compiler optimization bugs and bugs in the system headers are two very
different things. The former can be easily and without any harm disabled,
while the latter is completely unavoidable at all without a replacement.

-- 
Dmitry.