Introduce fast native caches and use it in String.search.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index b07792cd5070cbceb87dc5cfbfb68f8a35c6beb9..0167834338a9008e332bf56b8cfc3c5381da7ac9 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -76,6 +76,7 @@
 //             - MapCache
 //           - Context
 //           - GlobalContext
+//           - JSFunctionResultCache
 //       - String
 //         - SeqString
 //           - SeqAsciiString
@@ -2307,6 +2308,23 @@ class NumberDictionary: public Dictionary<NumberDictionaryShape, uint32_t> {
 };
 
 
+// JSFunctionResultCache caches results of some JSFunction invocation.
+// It is a fixed array with fixed structure:
+//   [0]: factory function
+//   [1]: finger index
+//   [2]: current cache size
+//   [3]: dummy field.
+// The rest of array are key/value pairs.
+class JSFunctionResultCache: public FixedArray {
+ public:
+  static const int kFactoryIndex = 0;
+  static const int kFingerIndex = kFactoryIndex + 1;
+  static const int kCacheSizeIndex = kFingerIndex + 1;
+  static const int kDummyIndex = kCacheSizeIndex + 1;
+  static const int kEntriesIndex = kDummyIndex + 1;
+};
+
+
 // ByteArray represents fixed sized byte arrays.  Used by the outside world,
 // such as PCRE, and also by the memory allocator and garbage collector to
 // fill in free blocks in the heap.