i965: Set kernel features before computing max GL version.

i965: Set kernel features before computing max GL version.

We check these bitfields when computing the Haswell max GL version.
We need to set them ahead of time, or they won't exist, and all our
checks will fail.  That sets the max core profile GL version to 4.2.

This introduces the bizarre situation where asking for a GL context
with version 4.3+ fails, but asking for a GL core profile context
with version <= 4.2 actually promotes you a 4.5 context.

GLX_MESA_query_renderer also reported the bogus 4.2 value.
Now it shows 4.5.

Cc: "17.0" <mesa-stable@lists.freedesktop.org>
Reported-and-tested-by: Rafael Ristovski <rafael.ristovski@gmail.com>