Extract CallStructure from Selector.

pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart

Index: pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart
diff --git a/pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart b/pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart
index c5cdc94635fe5760331445267d7670d70d465c24..7f5ff1d584fcc09a01da15778c627a2e97d30d11 100644
--- a/pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart
+++ b/pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart
@@ -236,8 +236,8 @@ abstract class BinaryArithmeticSpecializer extends InvokeDynamicSpecializer {
     if (selector.name == name) return selector;
     JavaScriptBackend backend = compiler.backend;
     Selector newSelector = new Selector(
-        SelectorKind.CALL, name, backend.interceptorsLibrary,
-        selector.argumentCount);
+        SelectorKind.CALL, new Name(name, backend.interceptorsLibrary),
+        new CallStructure(selector.argumentCount));
     return selector.mask == null
         ? newSelector
         : new TypedSelector(selector.mask, newSelector, compiler.world);