JRuby doesn't use libedit or readline, so those files are not read.
Furthermore, JRuby does not support vi editing mode.
irb(main):001:0> Readline.vi_editing_mode?
NotImplementedError: vi_editing_mode?() function is unimplemented on this machine
from org/jruby/ext/Readline.java:358:in `basic_quote_characters'
from (irb):1:in `evaluate'
from org/jruby/RubyKernel.java:1022:in `eval'
from org/jruby/RubyKernel.java:1338:in `loop'
from org/jruby/RubyKernel.java:1131:in `catch'
from org/jruby/RubyKernel.java:1131:in `catch'
from /usr/local/jruby/bin/jirb:13:in `(root)'
Admittedly, JRuby's Readline support has a lot to be desired.