* ext/fiddle/*: Adding fiddle library to wrap libffi

* test/fiddle/*: testing fiddle extension
* ext/dl/lib/dl.rb: Requiring fiddle if it is available
* ext/dl/lib/dl/callback.rb: using Fiddle if it is available
* ext/dl/lib/dl/func.rb: ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27640 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/fiddle/test_fiddle.rb

@@ -0,0 +1,19 @@
+require_relative 'helper'
+
+class TestFiddle < Fiddle::TestCase
+  def test_constants_match
+    [
+      :TYPE_VOID,
+      :TYPE_VOIDP,
+      :TYPE_CHAR,
+      :TYPE_SHORT,
+      :TYPE_INT,
+      :TYPE_LONG,
+      :TYPE_LONG_LONG,
+      :TYPE_FLOAT,
+      :TYPE_DOUBLE,
+    ].each do |name|
+      assert_equal(DL.const_get(name), Fiddle.const_get(name))
+    end
+  end
+end