Stop using superenv? method to dump ENV

Library/Homebrew/cmd/--env.rb

@@ -35,9 +35,13 @@ module Homebrew extend self
   end
 
   def dump_build_env env
-    build_env_keys(env).each do |key|
-      next if superenv? and %w{CC CXX OBJC OBJCXX}.include? key
+    keys = build_env_keys(env)
 
+    if env["CC"] == env["HOMEBREW_CC"]
+      %w[CC CXX OBJC OBJCXX].each { |key| keys.delete(key) }
+    end
+
+    keys.each do |key|
       value = env[key]
       print "#{key}: #{value}"
       case key