assembler: Use brw_set_dest() to encode the destination

A few notes:

I needed to introduce a brw context and compile structs. These are only
used to get which generation we are compiling code for, but eventually
we can use more of the infrastructure.

brw_set_dest() uses the destination register width to program the
instruction execution size.

The assembler can either take subnr in bytes or in number of elements,
so we need a resolve step when setting a brw_reg.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
3 files changed