Encode in name whether methods are class or instance side

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Mark literals and sequence nodes as having no cost.

Inspired by the change in JRuby: https://github.com/jruby/jruby/commit/0e4c83c904884f2206727b1e9627d86fdff7804a

Signed-off-by: Stefan Marr <git@stefan-marr.de>