Cache optimized code on shared function info.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 37c51d703db1679ba037990d411533734bfa9de5..fc2c77e2ca6173f92be23ee0557ae946830492da 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -3031,6 +3031,8 @@ ACCESSORS(BreakPointInfo, break_point_objects, Object, kBreakPointObjectsIndex)
 #endif
 
 ACCESSORS(SharedFunctionInfo, name, Object, kNameOffset)
+ACCESSORS_GCSAFE(SharedFunctionInfo, optimized_code_map, Object,
+                 kOptimizedCodeMapOffset)
 ACCESSORS_GCSAFE(SharedFunctionInfo, construct_stub, Code, kConstructStubOffset)
 ACCESSORS_GCSAFE(SharedFunctionInfo, initial_map, Object, kInitialMapOffset)
 ACCESSORS(SharedFunctionInfo, instance_class_name, Object,
@@ -3189,6 +3191,17 @@ void SharedFunctionInfo::set_strict_mode(bool value) {
 }
 
 
+void SharedFunctionInfo::BeforeVisitingPointers() {
+  if (IsInobjectSlackTrackingInProgress()) DetachInitialMap();
+
+  // Flush optimized code map on major GC.
+  // Note: we may experiment with rebuilding it or retaining entries
+  // which should survive as we iterate through optimized functions
+  // anyway.
+  set_optimized_code_map(Smi::FromInt(0));
+}
+
+
 ACCESSORS(CodeCache, default_cache, FixedArray, kDefaultCacheOffset)
 ACCESSORS(CodeCache, normal_type_cache, Object, kNormalTypeCacheOffset)