Reland r12342: Flush monomorphic ICs on context disposal instead of context exit.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index d6a3d2951a2d4a446b7510f87a5a50f838631b72..e48405460e903d79e4630fd1d1074b1cf26ef820 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -1103,7 +1103,10 @@ class Heap {
   void EnsureHeapIsIterable();
 
   // Notify the heap that a context has been disposed.
-  int NotifyContextDisposed() { return ++contexts_disposed_; }
+  int NotifyContextDisposed() {
+    flush_monomorphic_ics_ = true;
+    return ++contexts_disposed_;
+  }
 
   // Utility to invoke the scavenger. This is needed in test code to
   // ensure correct callback for weak global handles.
@@ -1620,6 +1623,8 @@ class Heap {
     global_ic_age_ = (global_ic_age_ + 1) & SharedFunctionInfo::ICAgeBits::kMax;
   }
 
+  bool flush_monomorphic_ics() { return flush_monomorphic_ics_; }
+
   intptr_t amount_of_external_allocated_memory() {
     return amount_of_external_allocated_memory_;
   }
@@ -1705,6 +1710,8 @@ class Heap {
 
   int global_ic_age_;
 
+  bool flush_monomorphic_ics_;
+
   int scan_on_scavenge_pages_;
 
 #if defined(V8_TARGET_ARCH_X64)