Remove dynamic exception specifications.
Dynamic exception specifications were a deprecated feature
that was complex and brittle in use.
They interacted badly with the type system,
which became a more significant issue in this International Standard
where (non-dynamic) exception specifications are part of the function type.
Effect on original feature:
A valid C++ 2014 function declaration,
member function declaration,
function pointer declaration,
or function reference declaration,
if it has a potentially throwing dynamic exception specification,
will be rejected as ill-formed in this International Standard.
Violating a non-throwing dynamic exception specification
will call terminate
rather than unexpected
and might not perform stack unwinding prior to such a call.