refactor: move bytes to builtin

builtin/byte.mbt

@@ -277,6 +277,48 @@ pub fn Byte::to_uint(self : Byte) -> UInt {
   self.to_int().reinterpret_as_uint()
 }
 
+///|
+/// Converts a byte value to an unsigned 64-bit integer.
+///
+/// Parameters:
+///
+/// * `byte` : The byte value to be converted.
+///
+/// Returns an unsigned 64-bit integer representation of the byte value.
+///
+/// Example:
+///
+/// ```mbt test
+/// let b = b'\xFF'
+/// inspect(b.to_uint64(), content="255")
+/// ```
+pub fn Byte::to_uint64(self : Byte) -> UInt64 {
+  self.to_uint().to_uint64()
+}
+
+///|
+/// Counts the number of 1-bits (population count) in the byte using bitwise operations.
+///
+/// Parameters:
+///
+/// * `self` : The byte value whose 1-bits are to be counted.
+///
+/// Returns the number of 1-bits in the byte.
+///
+/// Example:
+///
+/// ```mbt test
+/// let b = b'\x0F'
+/// inspect(b.popcnt(), content="4")
+/// ```
+pub fn Byte::popcnt(self : Byte) -> Int {
+  let mut n = self
+  n = (n & 0x55) + ((n >> 1) & 0x55)
+  n = (n & 0x33) + ((n >> 2) & 0x33)
+  n = (n & 0x0F) + ((n >> 4) & 0x0F)
+  n.to_int()
+}
+
 ///|
 /// Shifts the bits of the `Byte` value to the left by the specified number of
 /// positions.