Optimize isFinite and isNaN.

src/mksnapshot.cc

Index: src/mksnapshot.cc
diff --git a/src/mksnapshot.cc b/src/mksnapshot.cc
index a791dbba282302be09744c77c08179ea09fb6105..4f5fe96a9027e822f4b359555f436842a0774d81 100644
--- a/src/mksnapshot.cc
+++ b/src/mksnapshot.cc
@@ -29,6 +29,8 @@
 #include <bzlib.h>
 #endif
 #include <signal.h>
+#include <string>
+#include <map>
 
 #include "v8.h"
 
@@ -84,6 +86,16 @@ class CounterCollection {
 };
 
 
+// We statically allocate a set of local counters to be used if we
+// don't want to store the stats in a memory-mapped file
+static CounterCollection local_counters;
+
+
+typedef std::map<std::string, int*> CounterMap;
+typedef std::map<std::string, int*>::iterator CounterMapIterator;
+static CounterMap counter_table_;
+
+
 class Compressor {
  public:
   virtual ~Compressor() {}