iseq.c: preserve encoding

* iseq.c (iseqw_inspect): preserve path encoding in the result.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59065 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_iseq.rb

@@ -270,4 +270,12 @@ class TestISeq < Test::Unit::TestCase
       assert_equal(0, eval("0"))
     end;
   end
+
+  def test_inspect
+    %W[foo \u{30d1 30b9}].each do |name|
+      assert_match /@#{name}/, ISeq.compile("", name).inspect, name
+      m = ISeq.compile("class TestISeq::Inspect; def #{name}; end; instance_method(:#{name}); end").eval
+      assert_match /:#{name}@/, ISeq.of(m).inspect, name
+    end
+  end
 end