[base] Move hashmap allocator to a field

src/crankshaft/hydrogen-bce.cc

Index: src/crankshaft/hydrogen-bce.cc
diff --git a/src/crankshaft/hydrogen-bce.cc b/src/crankshaft/hydrogen-bce.cc
index d00d8ce25cc7b4a4009366daa840e32554f56608..3b5940dc9f813274f5b5e2993528b01fcabff5f9 100644
--- a/src/crankshaft/hydrogen-bce.cc
+++ b/src/crankshaft/hydrogen-bce.cc
@@ -316,16 +316,14 @@ BoundsCheckTable::BoundsCheckTable(Zone* zone)
 BoundsCheckBbData** BoundsCheckTable::LookupOrInsert(BoundsCheckKey* key,
                                                      Zone* zone) {
   return reinterpret_cast<BoundsCheckBbData**>(
-      &(ZoneHashMap::LookupOrInsert(key, key->Hash(),
-                                    ZoneAllocationPolicy(zone))->value));
+      &(ZoneHashMap::LookupOrInsert(key, key->Hash())->value));
 }
 
 
 void BoundsCheckTable::Insert(BoundsCheckKey* key,
                               BoundsCheckBbData* data,
                               Zone* zone) {
-  ZoneHashMap::LookupOrInsert(key, key->Hash(), ZoneAllocationPolicy(zone))
-      ->value = data;
+  ZoneHashMap::LookupOrInsert(key, key->Hash())->value = data;
 }