fixincludes and package updates

[Florian Weimer]

* Basin Ilya:

> When you build gcc from sources, a few headers are installed to
> /usr/lib/gcc/x86_64-redhat-linux/6.1.1/include-fixed/
>
> The exact list of these headers depends on packages installed. For example:
>     xorg-x11-proto-devel: X11/Xw32defs.h
>         unix => __unix__
>     openssl-devel: openssl/bn.h
>         linux => __linux__
>     libpaper-devel: paper.h
>         __STDC__ => __STRICT_ANSI__
>
> If you install a newer package version, the headers in "/usr/include/"
> get replaced and the headers in "include-fixed/" become outdated.
>
> How is this supposed to work?

It does not, which is why distribution builds generally disable
fixincludes or at the very least do not install the rewritten headers.