i965: Move the back-end compiler to src/intel/compiler

Mostly a dummy git mv with a couple of noticable parts:
 - With the earlier header cleanups, nothing in src/intel depends
files from src/mesa/drivers/dri/i965/
 - Both Autoconf and Android builds are addressed. Thanks to Mauro and
Tapani for the fixups in the latter
 - brw_util.[ch] is not really compiler specific, so it's moved to i965.

v2:
 - move brw_eu_defines.h instead of brw_defines.h
 - remove no-longer applicable includes
 - add missing vulkan/ prefix in the Android build (thanks Tapani)

v3:
 - don't list brw_defines.h in src/intel/Makefile.sources (Jason)
 - rebase on top of the oa patches

[Emil Velikov: commit message, various small fixes througout]
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/intel/vulkan/anv_pipeline.c

@@ -30,7 +30,7 @@
 #include "util/mesa-sha1.h"
 #include "common/gen_l3_config.h"
 #include "anv_private.h"
-#include "brw_nir.h"
+#include "compiler/brw_nir.h"
 #include "anv_nir.h"
 #include "spirv/nir_spirv.h"