i965: Skip recalculating URB allocations if the entry size didn't change.

We only get here if the VS/GS compiled programs change, but we can even
skip it if the VS/GS size didn't change.

Affects cairo runtime on glamor by -1.26471% +/- 0.674335% (n=234)

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
4 files changed