And it still is quite possible to change the paths in the script, so it would be more appropriate to test with
find -name '*.so*' |xargs strings | grep /lib.*86.*-linux-gnu
For those who are worried about whether it can be used in later releases: source code is preferable, but ISTR that one argument for dropping the old drivers was that Mesa 7.11 binary drivers could be used with newer Mesa.
And the reason that AMD and Nvidia don't use Gallium is that they have drivers written--why would you re-write a "working" driver just so you use a framework for making writing drivers easier?
Nvidia uses the same codebase for all drivers, and I think AMD shares a bit; that gets harder with two different frameworks.