Add constructors to signatures

test/codegen/expect/temps.js

Index: test/codegen/expect/temps.js
diff --git a/test/codegen/expect/temps.js b/test/codegen/expect/temps.js
index f60f0982d842a50b15f47b82bc683fca4b242d5e..75975a5605fa0a35defebfe5155de86da68cd920 100644
--- a/test/codegen/expect/temps.js
+++ b/test/codegen/expect/temps.js
@@ -12,6 +12,9 @@ var core = dart.import(core);
       this[_function] = func;
     }
   }
+  dart.setSignature(FormalCollision, {
+    constructors: () => ({FormalCollision: [FormalCollision, [core.int, core.int, core.Function]]})
+  });
   let _opt = Symbol('_opt');
   class OptionalArg extends core.Object {
     OptionalArg(opt) {
@@ -25,6 +28,12 @@ var core = dart.import(core);
     }
   }
   dart.defineNamedConstructor(OptionalArg, 'named');
+  dart.setSignature(OptionalArg, {
+    constructors: () => ({
+      OptionalArg: [OptionalArg, [], [core.int]],
+      named: [OptionalArg, [], {op: core.int}]
+    })
+  });
   function main() {
     core.print(new FormalCollision(1, 2, dart.fn(x => x)));
     core.print(new OptionalArg()[_opt]);