Log Message:
devel/ruby-parser: update to 3.12.0

=== 3.12.0 / 2018-12-04

* 3 minor enhancements:

  * 2.5: Allow rescue/ensure/else in normal do blocks. (presidentbeef)
  * Added stabby proc with do/end as block call argument. (presidentbeef)
  * Holy cow levels of optimization from presidentbeef. I write slow bad code.

* 1 bug fix:

  * Improve handling of single-quoted symbols and labels. (mvz)