i965: Add a new representation for Broadwell shader instructions.

i965: Add a new representation for Broadwell shader instructions.

Broadwell significantly changes the EU instruction encoding.  Many of
the fields got moved to different bit positions; some even got split
in two.

With so many changes, it was infeasible to continue using struct
brw_instruction.  We needed a new representation.

This new approach is a bit different: rather than a struct, I created a
class that has four DWords, and helper functions that read/write various
bits.  This has several advantages:

1. We can create several different names for the same bits.  For
   example, conditional modifiers, SFID for SEND instructions, and the
   MATH instruction's function opcode are all stored in bits 27:24.

   In each situation, we can use the appropriate setter function:
   set_sfid(), set_math_function(), or set_cond_modifier().  This
   is much easier to follow.

2. Since the fields are expressed using the original 128-bit numbers,
   the code to create the getter/setter functions follows the table in
   the documentation very closely.

To aid in debugging, I've enabled -fkeep-inline-functions when building
gen8_instruction.c.  Otherwise, these functions cannot be called by
gdb, making it insanely difficult to print out anything.

Kenneth Graunke wrote most of this code.  Damien Lespiau ported it to
C99.  Xiang Haihao added media fields.  Zhao Yakui added indirect
addressing support.  Eric Anholt added an assertion to make sure that
values fit in the alloted number of bits.

v2: Update for brw_reg_type_to_hw_type(), which necessitates passing
    brw_context pointers around everywhere.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Xiang, Haihao <haihao.xiang@intel.com>
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Acked-by: Matt Turner <mattst88@gmail.com>