Fix shared function info code replacement.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index a6f87981f62c8962c2b79cf8fa21f2edaafc4054..78aec58cc663f509776e610bdd143497330d2dde 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -4376,6 +4376,19 @@ void SharedFunctionInfo::set_code(Code* value, WriteBarrierMode mode) {
 }
 
 
+void SharedFunctionInfo::ReplaceCode(Code* value) {
+  // If the GC metadata field is already used then the function was
+  // enqueued as a code flushing candidate and we remove it now.
+  if (code()->gc_metadata() != NULL) {
+    CodeFlusher* flusher = GetHeap()->mark_compact_collector()->code_flusher();
+    flusher->EvictCandidate(this);
+  }
+
+  ASSERT(code()->gc_metadata() == NULL && value->gc_metadata() == NULL);
+  set_code(value);
+}
+
+
 ScopeInfo* SharedFunctionInfo::scope_info() {
   return reinterpret_cast<ScopeInfo*>(READ_FIELD(this, kScopeInfoOffset));
 }