added (number + null) dynamic support

std/hl/_std/Std.hx

@@ -102,6 +102,7 @@ class Std {
 			switch( tb.kind ) {
 			case HUI8, HUI16, HI32: return a + (b:Int);
 			case HF32, HF64: return a + (b:Float);
+			case HVOID: return a;
 			default:
 			}
 		case HF32, HF64:
@@ -109,6 +110,13 @@ class Std {
 			switch( tb.kind ) {
 			case HUI8, HUI16, HI32: return a + (b:Int);
 			case HF32, HF64: return a + (b:Float);
+			case HVOID: return a;
+			default:
+			}
+		case HVOID:
+			switch( tb.kind ) {
+			case HUI8, HUI16, HI32, HF32, HF64: return b;
+			case HVOID: return 0.;
 			default:
 			}
 		default: