configure.ac: add -Werror to default compiler options

[Rob Shearman]

2008/9/18 Austin English <austinenglish at gmail.com>:
> Should help avoid bugs like bug 15266 and promote more proper, portable code.

> Tried compiling Wine with -Werror, got a few interesting results. First one:
>
> austin at austin-desktop:~/wine-git/dlls/jscript$ make
> gcc -c -I. -I. -I../../include -I../../include  -D__WINESRC__  -D_REENTRANT
> -fPIC -Wall -Werror -pipe -fno-strict-aliasing -Wdeclaration-after-statement
> -Wwrite-strings -Wpointer-arith  -g -O2  -o engine.o engine.c
> cc1: warnings being treated as errors
> engine.c: In function 'var_statement_eval':
> engine.c:500: warning: 'hres' is used uninitialized in this function

Or it could just be that they had a different compiler version to you
and so the warning didn't appear for them. This is the trouble with
using -Werror in an uncontrolled environment - a developer using one
version of the compiler could commit code that compiles cleanly for
them, but not for another developer using a different compiler version
and so stop them from being able to build Wine. That's fine if we want
to do it, but we have to consider whether it is worth the hassle for
whatever increase in quality we get from it.

-- 
Rob Shearman