Simplify and optimize ToBoolean handling.

src/code-stubs.cc

Index: src/code-stubs.cc
===================================================================
--- src/code-stubs.cc	(revision 8868)
+++ src/code-stubs.cc	(working copy)
@@ -340,12 +340,11 @@
   if (IsEmpty()) stream->Add("None");
   if (Contains(UNDEFINED)) stream->Add("Undefined");
   if (Contains(BOOLEAN)) stream->Add("Bool");
+  if (Contains(NULL_TYPE)) stream->Add("Null");
   if (Contains(SMI)) stream->Add("Smi");
-  if (Contains(NULL_TYPE)) stream->Add("Null");
   if (Contains(SPEC_OBJECT)) stream->Add("SpecObject");
   if (Contains(STRING)) stream->Add("String");
   if (Contains(HEAP_NUMBER)) stream->Add("HeapNumber");
-  if (Contains(INTERNAL_OBJECT)) stream->Add("InternalObject");
 }
 
 
@@ -385,12 +384,14 @@
     return !object->IsUndetectableObject() &&
         String::cast(*object)->length() != 0;
   } else if (object->IsHeapNumber()) {
+    ASSERT(!object->IsUndetectableObject());
     Add(HEAP_NUMBER);
     double value = HeapNumber::cast(*object)->value();
-    return !object->IsUndetectableObject() && value != 0 && !isnan(value);
+    return value != 0 && !isnan(value);
   } else {
-    Add(INTERNAL_OBJECT);
-    return !object->IsUndetectableObject();
+    // We should never see an internal object at runtime here!
+    UNREACHABLE();
+    return true;
   }
 }
 
@@ -398,9 +399,14 @@
 bool ToBooleanStub::Types::NeedsMap() const {
   return Contains(ToBooleanStub::SPEC_OBJECT)
       || Contains(ToBooleanStub::STRING)
-      || Contains(ToBooleanStub::HEAP_NUMBER)
-      || Contains(ToBooleanStub::INTERNAL_OBJECT);
+      || Contains(ToBooleanStub::HEAP_NUMBER);
 }
 
 
+bool ToBooleanStub::Types::CanBeUndetectable() const {
+  return Contains(ToBooleanStub::SPEC_OBJECT)
+      || Contains(ToBooleanStub::STRING);
+}
+
+
 } }  // namespace v8::internal