* Compute --enable-languages in the Nix expression instead of in the
builder.
* Pass some flags through the Make command line instead of patching
the Makefiles.
* gcc: generate code for i686 by default (instead of i386).
* gcc: patch out some references to /lib and /usr/lib.
svn path=/nixpkgs/trunk/; revision=8722
b8dae869b3