merge revision(s) r47641,r47642,r47644: [Backport #10262]

	* win32/win32.c (VCSUP): nothing to do if this worktree is not under
	  any VCS (it means that the worktree may be from the release package).

	* win32/Makefile.sub (VCSUP): nothing to do if this worktree is not
	  under any VCS (it means that the worktree may be from the release
	  package).


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@47702 b2dd03c8-39d4-4d8f-98ff-823fe69b080e