brw: use default builder for urb handle adjustment

Be consistent with lowering that happens after, so that it gets a full
vector register and can stride into it.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38482>

src/intel/compiler/brw/brw_from_nir.cpp

@@ -5163,9 +5163,8 @@ adjust_handle_and_offset(const brw_builder &bld,
    unsigned adjustment = (urb_global_offset >> 11) << 11;
 
    if (adjustment) {
-      brw_builder ubld8 = bld.group(8, 0).exec_all();
       /* Allocate new register to not overwrite the shared URB handle. */
-      urb_handle = ubld8.ADD(urb_handle, brw_imm_ud(adjustment));
+      urb_handle = bld.ADD(urb_handle, brw_imm_ud(adjustment));
       urb_global_offset -= adjustment;
    }
 }