New approach to Crankshaft decision-making

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 95531df9d6ce8d29e6a53a251175da3a93218639..ce3ea1d6d0681fc30124c425eaa246a87ca0f9b7 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -1011,6 +1011,13 @@ class Isolate {
     thread_local_top_.top_lookup_result_ = top;
   }
 
+  bool context_exit_happened() {
+    return context_exit_happened_;
+  }
+  void set_context_exit_happened(bool context_exit_happened) {
+    context_exit_happened_ = context_exit_happened;
+  }
+
  private:
   Isolate();
 
@@ -1176,6 +1183,10 @@ class Isolate {
   unibrow::Mapping<unibrow::Ecma262Canonicalize> interp_canonicalize_mapping_;
   void* embedder_data_;
 
+  // The garbage collector should be a little more aggressive when it knows
+  // that a context was recently exited.
+  bool context_exit_happened_;
+
 #if defined(V8_TARGET_ARCH_ARM) && !defined(__arm__) || \
     defined(V8_TARGET_ARCH_MIPS) && !defined(__mips__)
   bool simulator_initialized_;