fixes #219, able to compile multiple entry points

test/codegen/expect/misc.txt

Index: test/codegen/expect/misc.txt
diff --git a/test/codegen/expect/misc.txt b/test/codegen/expect/misc.txt
index 8ae540eec5427548b80bac074c62588d91b2681a..d247049a0544c17c9895bd74c9dbb011c4570c13 100644
--- a/test/codegen/expect/misc.txt
+++ b/test/codegen/expect/misc.txt
@@ -1,10 +1,4 @@
 // Messages from compiling misc.dart
-info: line 19, column 27 of test/codegen/misc.dart: [DynamicInvoke] obj.x requires dynamic invoke
-    return obj is Base && obj.x == x && obj.y == y;
-                          ^^^^^
-info: line 19, column 41 of test/codegen/misc.dart: [DynamicInvoke] obj.y requires dynamic invoke
-    return obj is Base && obj.x == x && obj.y == y;
-                                        ^^^^^
-info: line 25, column 30 of test/codegen/misc.dart: [DynamicInvoke] obj.z requires dynamic invoke
-    return obj is Derived && obj.z == z && super == obj;
-                             ^^^^^
+info: [DynamicInvoke] obj.x requires dynamic invoke (test/codegen/misc.dart, line 19, col 27)
+info: [DynamicInvoke] obj.y requires dynamic invoke (test/codegen/misc.dart, line 19, col 41)
+info: [DynamicInvoke] obj.z requires dynamic invoke (test/codegen/misc.dart, line 25, col 30)