[Mesa-dev] V3 i965/Gallium ARB_get_program_binary support

[Timothy Arceri]

V3:
This is basically the V2 that Jordan sent with feedback addressed,
gallium support added, some minor functional changes such as only
storing the default uniforms to either disk or program binary cache
(rather than fixing them up later) and some refactoring to allow
greater code sharing between gallium and i965.

This series adds i965/gallium support for ARB_get_program_binary
with greater than 0 supported formats. Today we support this extension,
but advertise support for 0 formats. This series allows i965/gallium
to advertise support for 1 format.

This series defines a common Mesa format for ARB_get_program_binary,
along with helper functions to read and write the format. The binary
saved can only be reloaded on the exact same Mesa build using the
exact same hardware.

The i965/gallium implementation saves out a serialized nir/tgsi
represenation of the program. For i965 we can later add support for
saving the gen binary program as well. (We will still need the nir
program for state based recompiles.)

This implementation passes piglit, deqp and glcts functions. It also
works with (and fixes a crash in) Dead Island with makes use of the
extension.