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.
scalac may emit a ldc followed by an i2c, whereas javac does the
conversion (including zero extension if necessary) at compile time.
This commit ensures we handle the i2c case properly.
