iseq.c (iseq_data_to_ary): dump kw_arg as symbol

Fix RubyVM::InstructionSequence#to_a after r49517
Keywords were made symbols to fix [Bug #10831] [ruby-core:68031],
so we should dump symbols as-is instead of attempting to convert
them from IDs

* iseq.c (iseq_data_to_ary): dump kw_arg as symbol
* test/-ext-/iseq_load/test_iseq_load.rb: test kw_arg roundtrip
  [ruby-core:69891] [Bug #11338]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51190 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Wed Jul  8 04:42:27 2015  Eric Wong  <e@80x24.org>
+
+	* iseq.c (iseq_data_to_ary): dump kw_arg as symbol
+	* test/-ext-/iseq_load/test_iseq_load.rb: test kw_arg roundtrip
+	  [ruby-core:69891] [Bug #11338]
+
 Tue Jul  7 18:18:41 2015  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
 
 	* random.c (fill_random_bytes_syscall): fix compile error.

iseq.c

@@ -1795,7 +1795,7 @@ iseq_data_to_ary(rb_iseq_t *iseq)
 
 			orig_argc -= ci->kw_arg->keyword_len;
 			for (i = 0; i < ci->kw_arg->keyword_len; i++) {
-			    rb_ary_push(kw, ID2SYM(ci->kw_arg->keywords[i]));
+			    rb_ary_push(kw, ci->kw_arg->keywords[i]);
 			}
 			rb_hash_aset(e, ID2SYM(rb_intern("kw_arg")), kw);
 		    }

test/-ext-/iseq_load/test_iseq_load.rb

@@ -86,6 +86,15 @@ class TestIseqLoad < Test::Unit::TestCase
     assert_iseq_roundtrip(src)
   end
 
+  def test_kwarg
+    assert_iseq_roundtrip <<-'end;'
+      def foo(kwarg: :foo)
+        kwarg
+      end
+      foo(kwarg: :bar)
+    end;
+  end
+
   # FIXME: still failing
   def test_require_integration
     skip "iseq loader require integration tests still failing"