[runtime] Remove obsolete %GetPropertyNames runtime entry.

test/mjsunit/unbox-double-arrays.js

Index: test/mjsunit/unbox-double-arrays.js
diff --git a/test/mjsunit/unbox-double-arrays.js b/test/mjsunit/unbox-double-arrays.js
index 5ed404025f69bf08b9ced1c55d973d507590dfa1..8711ffdf3d954f98b98ae1f720e004e6647c2db6 100644
--- a/test/mjsunit/unbox-double-arrays.js
+++ b/test/mjsunit/unbox-double-arrays.js
@@ -489,17 +489,6 @@ test_for_in();
 test_for_in();
 test_for_in();
 
-function test_get_property_names() {
-  names = %GetPropertyNames(large_array3);
-  property_name_count = 0;
-  for (x in names) { property_name_count++; };
-  assertEquals(26, property_name_count);
-}
-
-test_get_property_names();
-test_get_property_names();
-test_get_property_names();
-
 // Test elements getters.
 assertEquals(expected_array_value(10), large_array3[10]);
 assertEquals(expected_array_value(-NaN), large_array3[2]);