compiler/nir: add an is_conversion field to nir_op_info

This is set to True only for numeric conversion opcodes.

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

src/compiler/nir/nir_opcodes_c.py

@@ -117,6 +117,7 @@ const nir_op_info nir_op_infos[nir_num_opcodes] = {
    .input_types = {
       ${ ", ".join("nir_type_" + type for type in opcode.input_types) }
    },
+   .is_conversion = ${"true" if opcode.is_conversion else "false"},
    .algebraic_properties =
       ${ "0" if opcode.algebraic_properties == "" else " | ".join(
             "NIR_OP_IS_" + prop.upper() for prop in