[Mesa-dev] i965: brw_draw_upload.c cleanup

[Eric Anholt]

This removes some bad code that got spammed into the hottest path of the
driver over time, and makes use of a few new things that didn't exist when the
driver was originally written.  Results for glb21 offscreen:

x before
+ after
+--------------------------------------------------------------------------+
|                   x         +                                            |
|           x xx    xx        +                                            |
|           x xxx xxxx+   ++  +++ ++                     x                 |
|    x x   xx+xx*xx****+x ++x+*++ +++                x   x        +        |
|x x x xx+*******x******x+**x+*++ ++++ ++++     * +  x   x xx+  x +++ ++  +|
|      |________|__M__A_______M_A_____|_________|                          |
+--------------------------------------------------------------------------+
    N           Min           Max        Median           Avg        Stddev
x  63        647.79        698.94        662.05     665.23365     12.512043
+  65        654.47        707.22         671.6     672.98954     13.209139
Difference at 95.0% confidence
	7.75589 +/- 4.46006
	1.16589% +/- 0.670451%
	(Student's t, pooled s = 12.8708)