Use a custom Struct for stack trace storage

src/execution.cc

 // Copyright 2014 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 "src/execution.h"
 
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
 #include "src/isolate-inl.h"
 #include "src/messages.h"
@@ skipping 416 matching lines @@
   // You should hold the ExecutionAccess lock when you call this.
   if (stored_limit != 0) {
     SetStackLimit(stored_limit);
   }
 }
 
 
 // --- C a l l s   t o   n a t i v e s ---
 
 
-Handle<String> Execution::GetStackTraceLine(Handle<Object> recv,
-                                            Handle<JSFunction> fun,
-                                            Handle<Object> pos,
-                                            Handle<Object> is_global) {
-  Isolate* isolate = fun->GetIsolate();
-  Handle<Object> strict_mode = isolate->factory()->ToBoolean(false);
-
-  MaybeHandle<Object> maybe_callsite =
-      CallSiteUtils::Construct(isolate, recv, fun, pos, strict_mode);
-  if (maybe_callsite.is_null()) {
-    isolate->clear_pending_exception();
-    return isolate->factory()->empty_string();
-  }
-
-  MaybeHandle<String> maybe_to_string =
-      CallSiteUtils::ToString(isolate, maybe_callsite.ToHandleChecked());
-  if (maybe_to_string.is_null()) {
-    isolate->clear_pending_exception();
-    return isolate->factory()->empty_string();
-  }
-
-  return maybe_to_string.ToHandleChecked();
-}
-
-
 void StackGuard::HandleGCInterrupt() {
   if (CheckAndClearInterrupt(GC_REQUEST)) {
     isolate_->heap()->HandleGCRequest();
   }
 }
 
 
 Object* StackGuard::HandleInterrupts() {
   if (FLAG_verify_predictable) {
     // Advance synthetic time by making a time request.
@@ skipping 28 matching lines @@
 
   isolate_->counters()->stack_interrupts()->Increment();
   isolate_->counters()->runtime_profiler_ticks()->Increment();
   isolate_->runtime_profiler()->MarkCandidatesForOptimization();
 
   return isolate_->heap()->undefined_value();
 }
 
 }  // namespace internal
 }  // namespace v8