[modules] Don't unnecessarily keep function alive after evaluation.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index aa8c9693442877c18b848d54e8e1e2ab3148ecc8..68fe89fca53af0108b04b8f1c6994725c7e50beb 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -7967,10 +7967,13 @@ class Module : public Struct {
   DECLARE_VERIFIER(Module)
   DECLARE_PRINTER(Module)
 
-  // The code representing this Module, either a SharedFunctionInfo or a
-  // JSFunction depending on whether it's been instantiated.
+  // The code representing this Module, or an abstraction thereof.
+  // This is either a SharedFunctionInfo or a JSFunction or a ModuleInfo
+  // depending on whether the module has been instantiated and evaluated.  See
+  // Module::ModuleVerify() for the precise invariant.
   DECL_ACCESSORS(code, Object)
 
+  // The export table.
   DECL_ACCESSORS(exports, ObjectHashTable)
 
   // The namespace object (or undefined).
@@ -7981,22 +7984,16 @@ class Module : public Struct {
   // ModuleInfo::module_requests.
   DECL_ACCESSORS(requested_modules, FixedArray)
 
-  // [[Evaluated]]: Whether this module has been evaluated. Modules
-  // are only evaluated a single time.
-  DECL_BOOLEAN_ACCESSORS(evaluated)
-
-  // Storage for [[Evaluated]].
-  DECL_INT_ACCESSORS(flags)
-
   // Hash for this object (a random non-zero Smi).
   DECL_INT_ACCESSORS(hash)
 
-  // Get the SharedFunctionInfo associated with the code.
-  inline SharedFunctionInfo* shared() const;
-
   // Get the ModuleInfo associated with the code.
   inline ModuleInfo* info() const;
 
+  inline bool instantiated() const;
+  inline bool evaluated() const;
+  inline void set_evaluated();
+
   // Implementation of spec operation ModuleDeclarationInstantiation.
   // Returns false if an exception occurred during instantiation, true
   // otherwise.
@@ -8022,8 +8019,7 @@ class Module : public Struct {
   static const int kCodeOffset = HeapObject::kHeaderSize;
   static const int kExportsOffset = kCodeOffset + kPointerSize;
   static const int kRequestedModulesOffset = kExportsOffset + kPointerSize;
-  static const int kFlagsOffset = kRequestedModulesOffset + kPointerSize;
-  static const int kEmbedderDataOffset = kFlagsOffset + kPointerSize;
+  static const int kEmbedderDataOffset = kRequestedModulesOffset + kPointerSize;

[adamk, 2016/10/14 18:01:02]

Looks like you'll need a merge here, as embedder data is no more.

   static const int kModuleNamespaceOffset = kEmbedderDataOffset + kPointerSize;
   static const int kHashOffset = kModuleNamespaceOffset + kPointerSize;
   static const int kSize = kHashOffset + kPointerSize;