intel/compiler: Don't use fs_visitor::bld in remaining places

The remaining users can simply create a new builder at_end() if needed.
In many places a new builder object is already being constructed, so
just give more specific instructions.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26323>

src/intel/compiler/brw_fs_nir.cpp

@@ -2218,6 +2218,7 @@ fs_visitor::emit_gs_control_data_bits(const fs_reg &vertex_count)
 
    struct brw_gs_prog_data *gs_prog_data = brw_gs_prog_data(prog_data);
 
+   const fs_builder bld = fs_builder(this, dispatch_width).at_end();
    const fs_builder abld = bld.annotate("emit control data bits");
    const fs_builder fwa_bld = bld.exec_all();