Use closure tracer to identify closures that are not passed to Function.apply

sdk/lib/_internal/compiler/implementation/inferrer/node_tracer.dart

Index: sdk/lib/_internal/compiler/implementation/inferrer/node_tracer.dart
diff --git a/sdk/lib/_internal/compiler/implementation/inferrer/node_tracer.dart b/sdk/lib/_internal/compiler/implementation/inferrer/node_tracer.dart
index b1ba510d50e0f7f1e3d443896b592548184b31fd..930db4f1d8e21a41c00416cb531759df72a4b74a 100644
--- a/sdk/lib/_internal/compiler/implementation/inferrer/node_tracer.dart
+++ b/sdk/lib/_internal/compiler/implementation/inferrer/node_tracer.dart
@@ -66,8 +66,9 @@ Set<String> doesNotEscapeMapSet = new Set<String>.from(
     'keys'
   ]);
 
-abstract class TracerVisitor implements TypeInformationVisitor {
-  final TypeInformation tracedType;
+abstract class TracerVisitor<T extends TypeInformation>
+    implements TypeInformationVisitor {
+  final T tracedType;
   final TypeGraphInferrerEngine inferrer;
   final Compiler compiler;
 
@@ -343,7 +344,7 @@ abstract class TracerVisitor implements TypeInformationVisitor {
         && inferrer.isNativeElement(element.enclosingElement)) {
       bailout('Passed to a native method');
     }
-    if (info.isClosurized()) {
+    if (info.isClosurized) {
       bailout('Returned from a closurized method');
     }
     if (isClosure(info.element)) {
@@ -352,6 +353,10 @@ abstract class TracerVisitor implements TypeInformationVisitor {
     if (compiler.backend.isNeededForReflection(info.element)) {
       bailout('Escape in reflection');
     }
+    if (!inferrer.compiler.backend
+        .canBeUsedForGlobalOptimizations(info.element)) {
+      bailout('Escape to code that has special backend treatment');
+    }
     if (isParameterOfListAddingMethod(info.element) ||
         isParameterOfMapAddingMethod(info.element)) {
       // These elements are being handled in