Patch: trivial optimizations

[Tom Tromey]

Anthony> Here are four simple optimizations I discovered by profiling
Anthony> MakeMimeType.

Yay, check these in.

Anthony> The Vector and StringTokenizer changes are essentially manual
Anthony> inlines.  As horrible as this sounds, I think the changes are
Anthony> relatively easy to swallow.

If we made VectorEnumeration a final class, would gcj automatically
inline the function call there?

Tom