Drop `make change` and tool/change_maker.rb

because we're not writing ChangeLog anymore.

common.mk

@@ -1459,9 +1459,6 @@ info-libruby_so: PHONY
 info-arch: PHONY
 	@echo arch=$(arch)
 
-change: PHONY
-	$(BASERUBY) -C "$(srcdir)" ./tool/change_maker.rb $(CHANGES) > change.log
-
 exam: check
 
 love: sudo-precheck up all test exam install
@@ -1514,7 +1511,6 @@ help: PHONY
 	"  install-cross:       install cross compiling stuff" \
 	"  clean:               clean for tarball" \
 	"  distclean:           clean for repository" \
-	"  change:              make change log template" \
 	"  golf:                for golfers" \
 	"  goruby:              same as golf" \
 	$(HELP_EXTRA_TASKS) \

tool/change_maker.rb

@@ -1,47 +0,0 @@
-#! ./miniruby
-
-# Used by "make change" to generate a list of files for a Changelog entry.
-# Run it via "make change" in the Ruby root directory.
-
-$:.unshift(File.expand_path("../../lib", __FILE__))
-require File.expand_path("../vcs", __FILE__)
-
-def diff2index(cmd, *argv)
-  lines = []
-  path = nil
-  output = `#{cmd} #{argv.join(" ")}`
-  if defined? Encoding::BINARY
-    output.force_encoding Encoding::BINARY
-  end
-  output.each_line do |line|
-    case line
-    when /^Index: (\S*)/, /^diff --git [a-z]\/(\S*) [a-z]\/\1/
-      path = $1
-    when /^@@\s*-[,\d]+ +\+(\d+)[,\d]*\s*@@(?: +([A-Za-z_][A-Za-z_0-9 ]*[A-Za-z_0-9]))?/
-      line = $1.to_i
-      ent = "\t* #{path}"
-      ent << " (#{$2})" if $2
-      lines << "#{ent}:"
-    end
-  end
-  lines.uniq!
-  lines.empty? ? nil : lines
-end
-
-vcs = begin
-  VCS.detect(".")
-rescue VCS::NotFoundError
-  nil
-end
-
-case vcs
-when VCS::SVN
-  cmd = "svn diff --diff-cmd=diff -x-pU0"
-  change = diff2index(cmd, ARGV)
-when VCS::GIT
-  cmd = "git diff -U0"
-  change = diff2index(cmd, ARGV) || diff2index(cmd, "--cached", ARGV)
-else
-  abort "does not seem to be under a vcs"
-end
-puts change if change