Register JSFixedArray as instantiated.

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

Index: pkg/compiler/lib/src/ssa/builder.dart
diff --git a/pkg/compiler/lib/src/ssa/builder.dart b/pkg/compiler/lib/src/ssa/builder.dart
index b6ef7c1ee7e58b670f82ce3436fba59f178f192a..b77f5de89d44f8700cb6f75b7ff8d9441d8167b3 100644
--- a/pkg/compiler/lib/src/ssa/builder.dart
+++ b/pkg/compiler/lib/src/ssa/builder.dart
@@ -3464,6 +3464,7 @@ class SsaBuilder extends ast.Visitor
       }
       js.Template code = js.js.parseForeignJS('new Array(#)');
       var behavior = new native.NativeBehavior();
+      behavior.typesInstantiated.add(expectedType);
       behavior.typesReturned.add(expectedType);
       // The allocation can throw only if the given length is a double or
       // outside the unsigned 32 bit range.