cast offset to intptr_t to avoid overflow

src/hotspot/share/oops/compressedKlass.cpp

@@ -96,7 +96,7 @@ void CompressedKlassPointers::sanity_check_after_initialization() {
 
   // Check that Klass range is fully engulfed in the encoding range
   const address encoding_start = _base;
-  const address encoding_end = (address)((intptr_t)_base + nth_bit(narrow_klass_pointer_bits() + _shift));
+  const address encoding_end = (address)((intptr_t)_base + (intptr_t)nth_bit(narrow_klass_pointer_bits() + _shift));
   ASSERT_HERE_2(_klass_range_start >= _base && _klass_range_end <= encoding_end,
                 "Resulting encoding range does not fully cover the class range");