Update revision.h in packages using `VCS#revision_header`

tool/lib/vcs.rb

@@ -204,7 +204,7 @@ class VCS
     revision_handler(rev).short_revision(rev)
   end
 
-  def revision_header(last, changed, modified, branch, title, limit: 20)
+  def revision_header(last, changed, modified, branch, title, limit: 20, time: true)
     short = short_revision(last)
     if /[^\x00-\x7f]/ =~ title and title.respond_to?(:force_encoding)
       title = title.dup.force_encoding("US-ASCII")
@@ -225,7 +225,7 @@ class VCS
       title = title.dump.sub(/\\#/, '#')
       code << "#define RUBY_LAST_COMMIT_TITLE #{title}"
     end
-    if modified
+    if modified and time
       t = modified.utc
       code << t.strftime('#define RUBY_RELEASE_DATETIME "%FT%TZ"')
     end

tool/make-snapshot

@@ -309,7 +309,7 @@ def package(vcs, rev, destdir, tmp = nil)
       warn "#{$0}: #{rev} not found"
       return
     end
-    revision = vcs.get_revisions(url)[1]
+    revision = (info = vcs.get_revisions(url))[1]
   end
 
   v = "ruby"
@@ -346,11 +346,7 @@ def package(vcs, rev, destdir, tmp = nil)
   end
 
   File.open("#{v}/revision.h", "wb") {|f|
-    short = vcs.short_revision(revision)
-    f.puts "#define RUBY_REVISION #{short.inspect}"
-    unless short == revision
-      f.puts "#define RUBY_FULL_REVISION #{revision.inspect}"
-    end
+    f.puts vcs.revision_header(*info, time: false)
   }
   version ||= (versionhdr = IO.read("#{v}/version.h"))[RUBY_VERSION_PATTERN, 1]
   version ||=