Can't share sampler varients across multiple tex units because the texture
pointer is in the sampler varient. That prevents different textures per unit.
Fixes progs/demos/multiarb, progs/glsl/samplers, etc.
Split into component pieces, stitch together at runtime using function
pointers. Make it possible to utilize the existing fastpaths as image-level
filters for generic mip-filtering routines.
Remove special case for rectangle filtering, as it can now be handled by
the 2d path.
As most of the mesa demo texturing was already covered by fast paths, its
harder to find examples of speedups, but tunnel gets a boost as mip-nearest
filtering is now able to access the img_2d_linear_wrap_POT functions
for sampling within a mipmap level.
The tile cache is a utility, it shouldn't know anything about the
entity which is making use of it (ie softpipe).
Remove softpipe parameter to all the tilecache function calls, and
also remove the need to keep a softpipe pointer in the sampler structs.
Update the Makefiles and includes for the new paths.
Note that there hasn't been no separation of the Makefiles yet, and make is
jumping all over the place. That will be taken care shortly. But for now, make
should work. It was tested with linux and linux-dri. Linux-cell and linux-llvm
might require some minor tweaks.
