intel/fs: Set NonPerspectiveBarycentricEnable when the interpolator needs it.

[anholt: changed to make all drivers do the right thing by moving the
payload barycentric check into the compiler]

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jason Ekstrand <jason.ekstrand@collabora.com>
Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17381>

src/intel/compiler/brw_compiler.h

@@ -889,10 +889,17 @@ struct brw_wm_prog_data {
 
    /**
     * Mask of which interpolation modes are required by the fragment shader.
-    * Used in hardware setup on gfx6+.
+    * Those interpolations are delivered as part of the thread payload. Used
+    * in hardware setup on gfx6+.
     */
    uint32_t barycentric_interp_modes;
 
+   /**
+    * Whether nonperspective interpolation modes are used by the
+    * barycentric_interp_modes or fragment shader through interpolator messages.
+    */
+   bool uses_nonperspective_interp_modes;
+
    /**
     * Mask of which FS inputs are marked flat by the shader source.  This is
     * needed for setting up 3DSTATE_SF/SBE.