Improve the performance of closure-converted code.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index c1cec8022088ff8267b686a9239c247baac77a38..0e7eb0dbe9d58394a245a527dea047a5f107bade 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -5486,7 +5486,8 @@ bool Function::HasGenericParent() const {
 }
 
 RawFunction* Function::implicit_closure_function() const {
-  if (IsClosureFunction() || IsSignatureFunction() || IsFactory()) {
+  if (IsClosureFunction() || IsConvertedClosureFunction() ||
+      IsSignatureFunction() || IsFactory()) {
     return Function::null();
   }
   const Object& obj = Object::Handle(raw_ptr()->data_);
@@ -5504,7 +5505,8 @@ RawFunction* Function::implicit_closure_function() const {
 }
 
 void Function::set_implicit_closure_function(const Function& value) const {
-  ASSERT(!IsClosureFunction() && !IsSignatureFunction());
+  ASSERT(!IsClosureFunction() && !IsSignatureFunction() &&
+         !IsConvertedClosureFunction());
   if (is_native()) {
     const Object& obj = Object::Handle(raw_ptr()->data_);
     ASSERT(obj.IsArray());
@@ -5625,6 +5627,9 @@ const char* Function::KindToCString(RawFunction::Kind kind) {
     case RawFunction::kImplicitClosureFunction:
       return "ImplicitClosureFunction";
       break;
+    case RawFunction::kConvertedClosureFunction:
+      return "ConvertedClosureFunction";
+      break;
     case RawFunction::kSignatureFunction:
       return "SignatureFunction";
       break;
@@ -6352,7 +6357,7 @@ RawFunction* Function::InstantiateSignatureFrom(
   if (IsConvertedClosureFunction()) {
     sig = Function::NewConvertedClosureFunction(
         String::Handle(zone, name()), parent, TokenPosition::kNoSource);
-    // TODO(sjindel): Kernel generic methods undone. Handle type parameters
+    // TODO(30455): Kernel generic methods undone. Handle type parameters
     // correctly when generic closures are supported. Until then, all type
     // parameters to this target are used for captured type variables, so they
     // aren't relevant to the type of the function.
@@ -6987,11 +6992,6 @@ RawFunction* Function::ConvertedClosureFunction() const {
   // Set closure function's end token to this end token.
   closure_function.set_end_token_pos(end_token_pos());
 
-  // The closurized method stub just calls into the original method and should
-  // therefore be skipped by the debugger and in stack traces.
-  closure_function.set_is_debuggable(false);
-  closure_function.set_is_visible(false);
-
   // Set closure function's formal parameters to this formal parameters,
   // removing the first parameter over which the currying is done, and adding
   // the closure class instance as the first parameter.  So, the overall number
@@ -7117,6 +7117,7 @@ void Function::BuildSignatureParameters(
 }
 
 RawInstance* Function::ImplicitStaticClosure() const {
+  ASSERT(IsImplicitStaticClosureFunction());
   if (implicit_static_closure() == Instance::null()) {
     Zone* zone = Thread::Current()->zone();
     const Context& context = Object::empty_context();
@@ -7299,7 +7300,7 @@ RawScript* Function::script() const {
       return script.raw();
     }
   }
-  if (IsClosureFunction()) {
+  if (IsClosureFunction() || IsConvertedClosureFunction()) {
     return Function::Handle(parent_function()).script();
   }
   const Object& obj = Object::Handle(raw_ptr()->owner_);