mesa: Convert the hash table for GL object ids to the open-addressing hash.

mesa: Convert the hash table for GL object ids to the open-addressing hash.

The previous 1023-entry chaining hash table never resized, so it was very
inefficient when there were many objects live.  While one could have an even
more efficient implementation than this (keep an array for genned names with
packed IDs, or take advantage of the fact that key == hash or key ==
*(uint32_t *)data to store less data), this is fairly fast, and I want a nice
replacement hash table for other parts of Mesa, too.

It improves Minecraft performance 12.3% +/- 1.4% (n=9), dropping hash lookups
from 8% of the profile to 0.5%.

I also tested cairo-gl, which should be a pessimal workload for this hash
table: around 247000 FBOs created and destroyed, only around 65 live at any
time, and few lookups of them between creation and destruction.  No
statistically significant performance difference at n=76 (mean 20.3/20.4
seconds, sd 2.8/3.2 seconds).  If I remove the >20 seconds outliers that
appear to be due to thermal throttling, there's possibly a .97% +/- 0.31%
performance win (n=61/59).  The choice of cutoff for outliers feels a lot like
cooking the data, but I've gone through this process 3 times for minor
iterations of the code with the same conclusion each time.

Reviewed-by: Brian Paul <brianp@vmware.com>
Acked-by: Chad Versace <chad.versace@linux.intel.com>
Acked-by: Kenneth Graunke <kenneth@whitecape.org> (v1)