Merge Ruby r47601

regparse.c: remove unused variable

* regparse.c (add_ctype_to_cc): suppress a warning by removing
  unused variable.
Merge branch 'master' into ruby-2.x
Merge Ruby r47602

regenc.h: shrink PosixBracketEntryType

* regenc.h (PosixBracketEntryType): shrink by embedding `name` and
  reordering.

Is this commit really needed?
I apply this commit only to the ruby-2.x branch for now.
Merge branch 'ruby-2.x' into ruby-2.x-buildenv