tile: Enable PI_STATIC_AND_HIDDEN

This does make ld.so very slightly larger (0.3%) and doesn't seem to
actually improve performance; in fact, my limited testing suggested a
slight (0.1%) performance decrease (running fork/exec of a no-op program
in a loop), but I didn't do enough testing to establish statistical
significance.

However, Roland agrees that it makes sense to switch tile to using
this path, since it's the more standard way.