Upgrade ASM to 6.2.1

In https://github.com/wildfly/wildfly/pull/11490#issuecomment-410845864 it was found that ASM 6.0 does not work on Java 10. The PR passes with ASM 6.2.1.

The other main user is CXF and rhn-engineering-ema reports:

CXF master has already upgraded ASM to 6.2, that implies it won't be problem to upgrade from 6.0 to 6.2.1 in Wildfly.

CC asoldano ropalkajperkins-rhnsmarlow@redhat.com