intel/nir: Drop an unneeded lower_constant_initializers call

Even though this is technically a step in the function inlining process
as laid out in nir_inline_functions.c, it's not really needed.  We
already have constant initializers lowered here and no new ones are
added by appending the softfp64 functions.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/intel/compiler/brw_nir.c

@@ -700,8 +700,6 @@ brw_preprocess_nir(const struct brw_compiler *compiler, nir_shader *nir)
    }
    assert(exec_list_length(&nir->functions) == 1);
 
-   OPT(nir_lower_constant_initializers, ~nir_var_function_temp);
-
    if (nir->info.stage == MESA_SHADER_GEOMETRY)
       OPT(nir_lower_gs_intrinsics);