Keep a canonical list of shared function infos.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 4f73eb42e7a057a77db18a8af84dd7a98773b508..d7ac24129ac5517458aeb36114f14c92897150fa 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -875,16 +875,23 @@ class AccessorPair;
 class AllocationSite;
 class AllocationSiteCreationContext;
 class AllocationSiteUsageContext;
+class Cell;
 class ConsString;
 class DictionaryElementsAccessor;
 class ElementsAccessor;
 class FixedArrayBase;
 class FunctionLiteral;
 class GlobalObject;
+class JSBuiltinsObject;
 class LayoutDescriptor;
 class LookupIterator;
+class ObjectHashTable;
 class ObjectVisitor;
+class PropertyCell;
+class SafepointEntry;
+class SharedFunctionInfo;
 class StringStream;
+class TypeFeedbackInfo;
 class TypeFeedbackVector;
 class WeakCell;
 
@@ -1733,9 +1740,6 @@ class JSReceiver: public HeapObject {
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver);
 };
 
-// Forward declaration for JSObject::GetOrCreateHiddenPropertiesHashTable.
-class ObjectHashTable;
-
 
 // The JSObject describes real heap allocated JavaScript objects with
 // properties.
@@ -4883,12 +4887,6 @@ class HandlerTable : public FixedArray {
 };
 
 
-// Forward declaration.
-class Cell;
-class PropertyCell;
-class SafepointEntry;
-class TypeFeedbackInfo;
-
 // Code describes objects with on-the-fly generated machine code.
 class Code: public HeapObject {
  public:
@@ -6456,6 +6454,10 @@ class Script: public Struct {
   // function from which eval was called where eval was called.
   DECL_ACCESSORS(eval_from_instructions_offset, Smi)
 
+  // [shared_function_infos]: weak fixed array containing all shared
+  // function infos created from this script.
+  DECL_ACCESSORS(shared_function_infos, Object)
+
   // [flags]: Holds an exciting bitfield.
   DECL_ACCESSORS(flags, Smi)
 
@@ -6503,6 +6505,10 @@ class Script: public Struct {
   // Get the JS object wrapping the given script; create it if none exists.
   static Handle<JSObject> GetWrapper(Handle<Script> script);
 
+  // Look through the list of existing shared function infos to find one
+  // that matches the function literal.  Return empty handle if not found.
+  MaybeHandle<SharedFunctionInfo> FindSharedFunctionInfo(FunctionLiteral* fun);
+
   // Dispatched behavior.
   DECLARE_PRINTER(Script)
   DECLARE_VERIFIER(Script)
@@ -6519,8 +6525,9 @@ class Script: public Struct {
   static const int kEvalFromSharedOffset = kIdOffset + kPointerSize;
   static const int kEvalFrominstructionsOffsetOffset =
       kEvalFromSharedOffset + kPointerSize;
-  static const int kFlagsOffset =
+  static const int kSharedFunctionInfosOffset =
       kEvalFrominstructionsOffsetOffset + kPointerSize;
+  static const int kFlagsOffset = kSharedFunctionInfosOffset + kPointerSize;
   static const int kSourceUrlOffset = kFlagsOffset + kPointerSize;
   static const int kSourceMappingUrlOffset = kSourceUrlOffset + kPointerSize;
   static const int kSize = kSourceMappingUrlOffset + kPointerSize;
@@ -6651,6 +6658,11 @@ class SharedFunctionInfo: public HeapObject {
                                     Handle<FixedArray> literals,
                                     BailoutId osr_ast_id);
 
+  // Set up the link between shared function info and the script. The shared
+  // function info is added to the list on the script.
+  static void SetScript(Handle<SharedFunctionInfo> shared,
+                        Handle<Object> script_object);
+
   // Layout description of the optimized code map.
   static const int kNextMapIndex = 0;
   static const int kEntriesStart = 1;
@@ -7534,9 +7546,6 @@ class JSGlobalProxy : public JSObject {
 };
 
 
-// Forward declaration.
-class JSBuiltinsObject;
-
 // Common super class for JavaScript global objects and the special
 // builtins global objects.
 class GlobalObject: public JSObject {