Granted, this is weird - but this is what openjdk does. Therefore,
some code that is compiled for openjdk (say, protobufs) will treat
calls to Map.hashCode as interface calls instead of virtual calls, as
they would have previously been under avian's classpath.
Also note that this error caused avian to abort in findInterfaceMethod
rather than throw an AbstractMethodError or somesuch - but that's a
problem for another day.
Previously, I used a shell script to extract modification date ranges
from the Git history, but that was complicated and unreliable, so now
every file just gets the same year range in its copyright header. If
someone needs to know when a specific file was modified and by whom,
they can look at the Git history themselves; no need to include it
redundantly in the header.
