Implement is-checks for static functions.

sdk/lib/_internal/compiler/implementation/ssa/codegen.dart

Index: sdk/lib/_internal/compiler/implementation/ssa/codegen.dart
diff --git a/sdk/lib/_internal/compiler/implementation/ssa/codegen.dart b/sdk/lib/_internal/compiler/implementation/ssa/codegen.dart
index fe8c5eeece7e28ffb77339d9aeaf72ba26473117..06b6576cdffe7ded824602c88cd2f35d6107d080 100644
--- a/sdk/lib/_internal/compiler/implementation/ssa/codegen.dart
+++ b/sdk/lib/_internal/compiler/implementation/ssa/codegen.dart
@@ -2270,6 +2270,11 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
     push(new js.Binary('==', pop(), new js.LiteralNull()));
   }
 
+  void checkNonNull(HInstruction input) {
+    use(input);
+    push(new js.Binary('!=', pop(), new js.LiteralNull()));
+  }
+
   void checkFunction(HInstruction input, DartType type) {
     checkTypeOf(input, '===', 'function');
     js.Expression functionTest = pop();
@@ -2394,6 +2399,12 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
                || Elements.isListSupertype(element, compiler)) {
       handleListOrSupertypeCheck(input, type);
       attachLocationToLast(node);
+    } else if (element.isTypedef()) {
+      checkNonNull(input);
+      js.Expression nullTest = pop();
+      checkType(input, type);
+      push(new js.Binary('&&', nullTest, pop()));
+      attachLocationToLast(node);
     } else if (types[input].canBePrimitive() || types[input].canBeNull()) {
       checkObject(input, '===');
       js.Expression objectTest = pop();