Optimize isFinite and isNaN.

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 7c690d26ba85d08bfc3d566425e78a3d5de4467c..5bb504d2da3cf29371f2a8df35e4704c3e533b93 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -47,6 +47,7 @@
 namespace v8 {
 namespace internal {
 
+class AstSentinels;
 class Bootstrapper;
 class CodeGenerator;
 class CodeRange;
@@ -877,6 +878,8 @@ class Isolate {
     return &objects_string_input_buffer_;
   }
 
+  AstSentinels* ast_sentinels() { return ast_sentinels_; }
+
   RuntimeState* runtime_state() { return &runtime_state_; }
 
   StaticResource<SafeStringInputBuffer>* compiler_safe_string_input_buffer() {
@@ -1135,6 +1138,7 @@ class Isolate {
   GlobalHandles* global_handles_;
   ContextSwitcher* context_switcher_;
   ThreadManager* thread_manager_;
+  AstSentinels* ast_sentinels_;
   RuntimeState runtime_state_;
   StaticResource<SafeStringInputBuffer> compiler_safe_string_input_buffer_;
   Builtins builtins_;