Added is_clock_gated attr to flops created via clockgate.cc pass

kernel/constids.inc

@@ -909,6 +909,7 @@ X(interface_type)
 X(interfaces_replaced_in_module)
 X(invertible_pin)
 X(iopad_external_pin)
+X(is_clock_gated)
 X(is_inferred)
 X(is_interface)
 X(it)

passes/techmap/clockgate.cc

@@ -448,7 +448,8 @@ struct ClockgatePass : public Pass {
 				ff.sig_clk = (*it).second.new_net;
 
 				// Rebuild the flop
-				(void)ff.emit();
+				Cell *new_ff = ff.emit();
+				new_ff->set_bool_attribute(ID::is_clock_gated);
 
 				gated_flop_count++;
 			}