use Arrays.copy or Arrays.copyOfRange where applicable

Arrays.copy is easier to use than System.arrayCopy.

primitiveCollections/src/main/java/org/lucares/collections/IntList.java

@@ -80,8 +80,7 @@ public final class IntList implements Serializable, Cloneable {
 	 *             if the specified {@link IntList} is null
 	 */
 	public IntList(final IntList intList) {
-		data = new int[intList.getCapacity()];
+		data = Arrays.copyOf(intList.data, intList.size());
-		System.arraycopy(intList.data, 0, data, 0, intList.size());
 		size = intList.size();
 		sorted = intList.sorted;
 	}
@@ -436,9 +435,7 @@ public final class IntList implements Serializable, Cloneable {
 		if (from + length > size) {
 			throw new IndexOutOfBoundsException("from: " + from + " length: " + length);
 		}
-		final int[] result = new int[length];
+		return Arrays.copyOfRange(data, from, from + length);
-		System.arraycopy(data, from, result, 0, length);
-		return result;
 	}
 
 	/**
@@ -511,9 +508,7 @@ public final class IntList implements Serializable, Cloneable {
 		if (size == 0) {
 			data = EMPTY_ARRAY;
 		} else {
-			final int[] newData = new int[size];
+			data = Arrays.copyOf(data, size);
-			System.arraycopy(data, 0, newData, 0, size);
-			data = newData;
 		}
 	}