Fix exception related warnings introduced by GCC 8.

C++11 deprecated the use of `throw(id)` in signatures, let's just remove
it. Negative testing still works in C++98 where using `throw(id)` is allowed so
it isn't useful to conditionally add it for previous versions C++.

Additionally, GCC now warns by default if an exception is caught by value when
its type is polymorphic (-Wcatch-value).

Change-Id: I7d68c82935b4796dd0fc449228ae8df4f548574d