mesa: fix double-freeing of dispatch tables inside glBegin/End.

We allocate dispatch tables for BeginEnd and OutsideBeginEnd.  But
when we destroy the context we were freeing the BeginEnd and Exec
tables.  If Exec==BeginEnd we did a double-free.  This would happen
if the context was destroyed while inside a glBegin/End pair.  Now
free the BeginEnd and OutsideBeginEnd pointers.

Cc: "10.1", "10.2" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
(cherry picked from commit ef6b6658f91bd5871739bdb71a08042f26abe389)
cherry-ignore: Roland and Michel agreed to drop these patches.

The first was apparently not entirely suitable for stable, (and buggy). And
the second existed only to fix a bug in the first. So without the first, we
don't need either.
nv50/ir: fix integer mul lowering for u32 x u32 -> high u32

UNION appears to expect that all of its sources are conditionally
defined. Otherwise it inserts an unpredicated mov instruction which
overwrites the desired result. This fixes tests that use UMUL_HI, and
much less directly, unsigned integer division by a constant, which uses
this functionality in a peephole pass.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: "10.1 10.2" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
(cherry picked from commit 5b8f1a0f7c5b1412577a913d374192a2329fa615)