* array.c, gc.c: move ary_unprotect_logging() into
  rb_gc_unprotect_logging() which is general version
* include/ruby/ruby.h: add USE_RGENGC_LOGGING_WB_UNPROTECT
  to enable.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42151 b2dd03c8-39d4-4d8f-98ff-823fe69b080e