i965: Introduce state flag for blorp

In the past, BLORP has clobbered all BRW_NEW_* state flags, to trigger
re-emission of the entire 3D pipeline on the next draw.  However, there
are some packets BLORP simply leaves alone, so there's no need to
re-emit them.  Trying to reduce the set of dirty bits flagged after
BLORP runs is tricky.

Instead, we introduce a BRW_NEW_BLORP flag.  This should be set on any
atom which emits a packet that BLORP also emits.  When BLORP runs, it
will flag BRW_NEW_BLORP, causing those packets to get re-emitted.

This also makes it easy to avoid re-emitting specific atoms - we can
simply drop the BRW_NEW_BLORP flag on those.

To start, we assume that all packets need to be re-emitted.  This is the
safest approach and closest to the existing code's behavior.  Many of
these are obviously not required, and can be dropped in subsequent
patches.

Signed-off-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>