Support runtime check of function types.

sdk/lib/_internal/compiler/implementation/resolution/members.dart

Index: sdk/lib/_internal/compiler/implementation/resolution/members.dart
diff --git a/sdk/lib/_internal/compiler/implementation/resolution/members.dart b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
index e422dbe5bd756c7371f611d7f7d15a6993d305c7..04aa685fade9e6543db7053012bafd03d4c899a6 100644
--- a/sdk/lib/_internal/compiler/implementation/resolution/members.dart
+++ b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
@@ -1901,6 +1901,12 @@ class ResolverVisitor extends MappingVisitor<Element> {
       }
       parameterNodes = parameterNodes.tail;
     });
+    if (inCheckContext) {
+      functionParameters.forEachParameter((Element element) {
+        compiler.enqueuer.resolution.registerIsCheck(
+            element.computeType(compiler), mapping);
+      });
+    }
   }
 
   visitCascade(Cascade node) {
@@ -1998,6 +2004,7 @@ class ResolverVisitor extends MappingVisitor<Element> {
     scope = oldScope;
     enclosingElement = previousEnclosingElement;
 
+    world.registerClosurizedMember(function, mapping);
     world.registerInstantiatedClass(compiler.functionClass, mapping);
   }