Add check for u128 max value

Author: cgm616

clippy_lints/src/xor_used_as_pow.rs

@@ -41,7 +41,7 @@ impl EarlyLintPass for XorUsedAsPow {
             if let LitKind::Int(rhs, _) = lit.node;
             then {
                 if lhs == 2 {
-                    if rhs == 8 || rhs == 16 || rhs == 32 || rhs == 64 {
+                    if rhs == 8 || rhs == 16 || rhs == 32 || rhs == 64 || rhs == 128 {
                         span_lint_and_sugg(
                             cx,
                             XOR_USED_AS_POW,