i965, anv: Use NIR FragCoord re-center and y-transform passes.

This handles gl_FragCoord transformations and other window system vs.
user FBO coordinate system flipping by multiplying/adding uniform
values, rather than recompiles.

This is much better because we have no decent way to guess whether
the application is going to use a shader with the window system FBO
or a user FBO, much less the drawable height.  This led to a lot of
recompiles in many applications.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>

src/intel/vulkan/anv_pipeline.c

@@ -142,6 +142,11 @@ anv_shader_compile_to_nir(struct anv_device *device,
 
       free(spec_entries);
 
+      if (stage == MESA_SHADER_FRAGMENT) {
+         nir_lower_wpos_center(nir);
+         nir_validate_shader(nir);
+      }
+
       nir_lower_returns(nir);
       nir_validate_shader(nir);