Add hulk.util and round_up_power_2()

src/hulk/util.d

@@ -0,0 +1,17 @@
+/**
+ * HULK utility functions.
+ */
+module hulk.util;
+
+/**
+ * Round a value up to the next power of 2.
+ *
+ * @param v Value to round up.
+ * @param p Power of 2 to round up to.
+ *
+ * @return Rounded up value.
+ */
+T round_up_power_2(T)(T v, T p)
+{
+    return (v + p - 1u) & ~(p - 1u);
+}