bugfixes in typedef, goto, enum

Bugfixes:

- "typedef int T;" must not clash (namespace-wise) with "T: goto T;"
following it

- "enum { EE0 };" must compile without a tag and without an instance
variable

- the following must compile as well:
{
enum { E = 99 };
{
enum { E = E + 1, F = E };
}
}