Ensure there is some space on JS stack available for bootstrapping.

src/isolate.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
 
 #include "src/v8.h"
@@ skipping 2754 matching lines @@
   }
   if (new_length == 0) {
     heap()->set_detached_contexts(heap()->empty_fixed_array());
   } else if (new_length < length) {
     heap()->RightTrimFixedArray<Heap::CONCURRENT_TO_SWEEPER>(
         *detached_contexts, length - new_length);
   }
 }
 
 
-bool StackLimitCheck::JsHasOverflowed() const {
+bool StackLimitCheck::JsHasOverflowed(uintptr_t gap) const {
   StackGuard* stack_guard = isolate_->stack_guard();
 #ifdef USE_SIMULATOR
   // The simulator uses a separate JS stack.
   Address jssp_address = Simulator::current(isolate_)->get_sp();
   uintptr_t jssp = reinterpret_cast<uintptr_t>(jssp_address);
-  if (jssp < stack_guard->real_jslimit()) return true;
+  if (jssp - gap < stack_guard->real_jslimit()) return true;
 #endif  // USE_SIMULATOR
-  return GetCurrentStackPosition() < stack_guard->real_climit();
+  return GetCurrentStackPosition() - gap < stack_guard->real_climit();
 }
 
 
 SaveContext::SaveContext(Isolate* isolate)
     : isolate_(isolate), prev_(isolate->save_context()) {
   if (isolate->context() != NULL) {
     context_ = Handle<Context>(isolate->context());
   }
   isolate->set_save_context(this);
 
   c_entry_fp_ = isolate->c_entry_fp(isolate->thread_local_top());
 }
 
 
 bool PostponeInterruptsScope::Intercept(StackGuard::InterruptFlag flag) {
   // First check whether the previous scope intercepts.
   if (prev_ && prev_->Intercept(flag)) return true;
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8