make-snapshot: suppress warnings

* tool/make-snapshot: suppress warnings for uninitialized global
  variables.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48836 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
vcs.rb: IO.pread

* tool/vcs.rb (IO.pread): method to read command output without
  shell.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48837 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2014-12-15

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48838 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
vcs.rb: non-string path

* tool/vcs.rb (VCS#get_revisions, VCS::SVN.get_revisions): allow
  path to be other than a string.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48839 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
vcs.rb: abstract

* tool/vcs.rb: abstract VCS interfaces from make-snapshot.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48840 b2dd03c8-39d4-4d8f-98ff-823fe69b080e