Convert damage modifiers to integer percentages.

OpenRA.Game/Traits/Util.cs

@@ -138,5 +138,15 @@ namespace OpenRA.Traits
 			var cells = target.Positions.Select(p => w.Map.CellContaining(p)).Distinct();
 			return ExpandFootprint(cells, true);
 		}
+
+		public static int ApplyPercentageModifiers(int number, IEnumerable<int> percentages)
+		{
+			// See the comments of PR#6079 for a faster algorithm if this becomes a performance bottleneck
+			var a = (decimal)number;
+			foreach (var p in percentages)
+				a *= p / 100m;
+
+			return (int)a;
+		}
 	}
 }