fix: fix while loop in ReverseImpl (#4525)

Reference: https://docs.scala-lang.org/scala3/reference/dropped-features/do-while.html#why-drop-the-construct-1

Signed-off-by: unlsycn <[email protected]>

src/main/scala/chisel3/util/BitwiseImpl.scala

@@ -56,13 +56,12 @@ private[chisel3] trait ReverseImpl {
         var res = in
         var shift = length >> 1
         var mask = ((BigInt(1) << length) - 1).asUInt(length.W)
-        var initial = true
-        while (initial || shift > 0) {
-          initial = false
+        while ({
           mask = mask ^ (mask(length - shift - 1, 0) << shift)
-          res = ((res >> shift) & mask) | ((res(length - shift - 1, 0) << shift) & !mask)
+          res = ((res >> shift) & mask) | ((res(length - shift - 1, 0) << shift) & ~mask)
           shift = shift >> 1
-        }
+          shift > 0
+        }) {}
         res
       case _ =>
         val half = (1 << log2Ceil(length)) / 2