Cast to uint instead of nuint in {ReadOnly}Span.{Try}CopyTo (#51083)

src/libraries/System.Private.CoreLib/src/System/ReadOnlySpan.cs

@@ -274,7 +274,7 @@ public void CopyTo(Span<T> destination)
 
             if ((uint)_length <= (uint)destination.Length)
             {
-                Buffer.Memmove(ref destination._pointer.Value, ref _pointer.Value, (nuint)_length);
+                Buffer.Memmove(ref destination._pointer.Value, ref _pointer.Value, (uint)_length);
             }
             else
             {
@@ -295,7 +295,7 @@ public bool TryCopyTo(Span<T> destination)
             bool retVal = false;
             if ((uint)_length <= (uint)destination.Length)
             {
-                Buffer.Memmove(ref destination._pointer.Value, ref _pointer.Value, (nuint)_length);
+                Buffer.Memmove(ref destination._pointer.Value, ref _pointer.Value, (uint)_length);
                 retVal = true;
             }
             return retVal;

src/libraries/System.Private.CoreLib/src/System/Span.cs

@@ -348,7 +348,7 @@ public void CopyTo(Span<T> destination)
 
             if ((uint)_length <= (uint)destination.Length)
             {
-                Buffer.Memmove(ref destination._pointer.Value, ref _pointer.Value, (nuint)_length);
+                Buffer.Memmove(ref destination._pointer.Value, ref _pointer.Value, (uint)_length);
             }
             else
             {
@@ -369,7 +369,7 @@ public bool TryCopyTo(Span<T> destination)
             bool retVal = false;
             if ((uint)_length <= (uint)destination.Length)
             {
-                Buffer.Memmove(ref destination._pointer.Value, ref _pointer.Value, (nuint)_length);
+                Buffer.Memmove(ref destination._pointer.Value, ref _pointer.Value, (uint)_length);
                 retVal = true;
             }
             return retVal;