nir: Drop nir_dest

Instead, we replace every use of it with nir_def.  Most of this commit
was generated by sed:

   sed -i -e 's/dest.ssa/def/g' src/**/*.h src/**/*.c src/**/*.cpp

A few manual fixups were required in lima and the nir_legacy code.

Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24674>

src/intel/compiler/brw_fs.cpp

@@ -7404,7 +7404,7 @@ brw_compute_barycentric_interp_modes(const struct intel_device_info *devinfo,
             }
 
             /* Ignore WPOS; it doesn't require interpolation. */
-            if (!is_used_in_not_interp_frag_coord(&intrin->dest.ssa))
+            if (!is_used_in_not_interp_frag_coord(&intrin->def))
                continue;
 
             nir_intrinsic_op bary_op = intrin->intrinsic;