Reland "Add mechanism to postpone interrupts selectively."

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index ed2ed33ac74a432d44e9c7d5b3e20f2fc5b325bb..e2ab3fafa5a03dbd184ccebb1ffec7439be7ad31 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -1420,22 +1420,29 @@ class StackLimitCheck BASE_EMBEDDED {
 // account.
 class PostponeInterruptsScope BASE_EMBEDDED {
  public:
-  explicit PostponeInterruptsScope(Isolate* isolate)
-      : stack_guard_(isolate->stack_guard()), isolate_(isolate) {
-    ExecutionAccess access(isolate_);
-    stack_guard_->thread_local_.postpone_interrupts_nesting_++;
-    stack_guard_->DisableInterrupts();
+  PostponeInterruptsScope(Isolate* isolate,
+                          int intercept_mask = StackGuard::ALL_INTERRUPTS)
+      : stack_guard_(isolate->stack_guard()),
+        intercept_mask_(intercept_mask),
+        intercepted_flags_(0) {
+    stack_guard_->PushPostponeInterruptsScope(this);
   }
 
   ~PostponeInterruptsScope() {
-    ExecutionAccess access(isolate_);
-    if (--stack_guard_->thread_local_.postpone_interrupts_nesting_ == 0) {
-      stack_guard_->EnableInterrupts();
-    }
+    stack_guard_->PopPostponeInterruptsScope();
   }
+
+  // Find the bottom-most scope that intercepts this interrupt.
+  // Return whether the interrupt has been intercepted.
+  bool Intercept(StackGuard::InterruptFlag flag);
+
  private:
   StackGuard* stack_guard_;
-  Isolate* isolate_;
+  int intercept_mask_;
+  int intercepted_flags_;
+  PostponeInterruptsScope* prev_;
+
+  friend class StackGuard;
 };