RFR: 8223064: Minor cleanups in ResolvedMethodTable

[Stefan Karlsson]

Hi all,

Please review these minor cleanups in the ResolvedMethodTable.

http://cr.openjdk.java.net/~stefank/8223064/webrev.01/
https://bugs.openjdk.java.net/browse/JDK-8223064

- Remove unused EXCEPTION_MARK - unnecessarily copied from StringTable
- Reuse existing LogTarget
- Remove unreachable return statement

Thanks,
StefanK