Fix incorrect ASSERT when recording code age stats.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 96cda586b7c9ea464bc7b1fd39d38c160b34e207..bbf6737116386c319551b263f58091a06b42c417 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -1823,7 +1823,7 @@ class Heap {
 
   void RecordCodeSubTypeStats(int code_sub_type, int code_age, size_t size) {
     ASSERT(code_sub_type < Code::NUMBER_OF_KINDS);
-    ASSERT(code_age < Code::kLastCodeAge);
+    ASSERT(code_age <= Code::kLastCodeAge);
     object_counts_[FIRST_CODE_KIND_SUB_TYPE + code_sub_type]++;
     object_sizes_[FIRST_CODE_KIND_SUB_TYPE + code_sub_type] += size;
     object_counts_[FIRST_CODE_AGE_SUB_TYPE + code_age]++;