glsl: Bitwise conversion operator support in the software renderers.

TGSI doesn't need an opcode, since registers are untyped (but beware
once doubles come into the scene).  Mesa IR doesn't handle native
integers, so trying to handle them there is worthless, the case
entries are only added for warning reasons.

It was only tested with softpipe, since llvmpipe doesn't support glsl
1.3 yet.

Signed-off-by: Olivier Galibert <galibert@pobox.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/mesa/program/ir_to_mesa.cpp

@@ -1407,6 +1407,11 @@ ir_to_mesa_visitor::visit(ir_expression *ir)
       emit(ir, OPCODE_SNE, result_dst,
 			  op[0], src_reg_for_float(0.0));
       break;
+   case ir_unop_bitcast_f2i: // Ignore these 4, they can't happen here anyway
+   case ir_unop_bitcast_f2u:
+   case ir_unop_bitcast_i2f:
+   case ir_unop_bitcast_u2f:
+      break;
    case ir_unop_trunc:
       emit(ir, OPCODE_TRUNC, result_dst, op[0]);
       break;