Fix build with ancient NaCl toolchain.

src/serialize.cc

Index: src/serialize.cc
diff --git a/src/serialize.cc b/src/serialize.cc
index d13b00cfccab95f4fc7cae16ca0676720ddd8bb8..0e5ab064bcfe5df33d3029dc9526c58c3604b37f 100644
--- a/src/serialize.cc
+++ b/src/serialize.cc
@@ -314,7 +314,7 @@ void ExternalReferenceTable::PopulateTable(Isolate* isolate) {
 #undef IC_ENTRY
   };  // end of ref_table[].
 
-  for (size_t i = 0; i < arraysize(ref_table); ++i) {
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(ref_table); ++i) {
     AddFromId(ref_table[i].type,
               ref_table[i].id,
               ref_table[i].name,
@@ -340,7 +340,7 @@ void ExternalReferenceTable::PopulateTable(Isolate* isolate) {
   };  // end of stats_ref_table[].
 
   Counters* counters = isolate->counters();
-  for (size_t i = 0; i < arraysize(stats_ref_table); ++i) {
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(stats_ref_table); ++i) {
     Add(reinterpret_cast<Address>(GetInternalPointer(
             (counters->*(stats_ref_table[i].counter))())),
         STATS_COUNTER,