Copier should copy InvokeMethod calling convention

pkg/compiler/lib/src/cps_ir/cps_fragment.dart

Index: pkg/compiler/lib/src/cps_ir/cps_fragment.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_fragment.dart b/pkg/compiler/lib/src/cps_ir/cps_fragment.dart
index a4bd305f9f58737621f6ce1d5a4ad933d708a2a1..cc06b498c2f77e038b62b7ce2b03870a4900de10 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_fragment.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_fragment.dart
@@ -135,8 +135,9 @@ class CpsFragment {
       List<Primitive> arguments,
       [CallingConvention callingConvention = CallingConvention.Normal]) {
     InvokeMethod invoke =
-        new InvokeMethod(receiver, selector, mask, arguments, sourceInformation)
-            ..callingConvention = callingConvention;
+        new InvokeMethod(receiver, selector, mask, arguments,
+                         sourceInformation: sourceInformation,
+                         callingConvention: callingConvention);
     return letPrim(invoke);
   }