Fix memory corruption in JSFunctionResultCache::Clear.

src/objects-inl.h

Index: src/objects-inl.h
===================================================================
--- src/objects-inl.h	(revision 5738)
+++ src/objects-inl.h	(working copy)
@@ -1923,7 +1923,9 @@
 void JSFunctionResultCache::Clear() {
   int cache_size = Smi::cast(get(kCacheSizeIndex))->value();
   Object** entries_start = RawField(this, OffsetOfElementAt(kEntriesIndex));
-  MemsetPointer(entries_start, Heap::the_hole_value(), cache_size);
+  MemsetPointer(entries_start,
+                Heap::the_hole_value(),
+                cache_size - kEntriesIndex);
   MakeZeroSize();
 }