fix warnings emitted by clang
Merge pull request #2469 from WalterBright/fix-clang-warnings

fix warnings emitted by clang
fix issue 10834 - cannot use cast(void)expr if the type of expr is a
struct
Merge pull request #2482 from hpohl/10834

fix issue 10834 - cannot use cast(void)expr if the type of expr is a struct