i965: Implement a disassembler for Broadwell's new instruction encoding.

i965: Implement a disassembler for Broadwell's new instruction encoding.

Heavily based on Keith Packard's existing brw_disasm.c code.  I've tried
to go through most of the pieces (like SFIDs) and update the lists to
include features added in recent generations.

v2: Port to use the C-based instruction emitters.  This allows us to use
    C99 array initializers, which tidies up some of the code.

v3: Improve decoding of render target write messages.

v4: Update for BRW_REGISTER_TYPE becoming an abstraction.

v5: Rebase on Chris Forbes' SFID message defines.

v6: Fix disassembly of UV immediates; remove silly casts.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>