ARGV: Deprecate ARGV.keep_tmp?

Library/Homebrew/build.rb

@@ -119,7 +119,7 @@ class Build
         # which is not known until after the formula has been staged.
         ENV["HOMEBREW_FORMULA_PREFIX"] = formula.prefix
 
-        staging.retain! if ARGV.keep_tmp?
+        staging.retain! if Homebrew.args.keep_tmp?
         formula.patch
 
         if Homebrew.args.git?

Library/Homebrew/dev-cmd/update-test.rb

@@ -123,6 +123,6 @@ module Homebrew
       end
     end
   ensure
-    FileUtils.rm_rf "update-test" unless args.keep_tmp?
+    FileUtils.rm_rf "update-test" unless Homebrew.args.keep_tmp?
   end
 end

Library/Homebrew/extend/ARGV.rb

@@ -31,10 +31,6 @@ module HomebrewArgvExtension
     flag?("--debug") || !ENV["HOMEBREW_DEBUG"].nil?
   end
 
-  def keep_tmp?
-    include? "--keep-tmp"
-  end
-
   def homebrew_developer?
     !ENV["HOMEBREW_DEVELOPER"].nil?
   end

Library/Homebrew/formula.rb

@@ -1126,7 +1126,7 @@ class Formula
   def brew
     @prefix_returns_versioned_prefix = true
     stage do |staging|
-      staging.retain! if ARGV.keep_tmp?
+      staging.retain! if Homebrew.args.keep_tmp?
       prepare_patches
 
       begin
@@ -1765,7 +1765,7 @@ class Formula
     Utils.set_git_name_email!
 
     mktemp("#{name}-test") do |staging|
-      staging.retain! if ARGV.keep_tmp?
+      staging.retain! if Homebrew.args.keep_tmp?
       @testpath = staging.tmpdir
       test_env[:HOME] = @testpath
       setup_home @testpath

Library/Homebrew/formula_installer.rb

@@ -703,7 +703,7 @@ class FormulaInstaller
     args << "--debug" if debug?
     args << "--cc=#{ARGV.cc}" if ARGV.cc
     args << "--default-fortran-flags" if ARGV.include? "--default-fortran-flags"
-    args << "--keep-tmp" if ARGV.keep_tmp?
+    args << "--keep-tmp" if Homebrew.args.keep_tmp?
 
     if ARGV.env
       args << "--env=#{ARGV.env}"