[builtins] Add receiver to builtin exit frames

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 "src/isolate.h"
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
@@ skipping 415 matching lines @@
         }
       } break;
 
       case StackFrame::BUILTIN_EXIT: {
         BuiltinExitFrame* exit_frame = BuiltinExitFrame::cast(frame);
         Handle<JSFunction> fun = handle(exit_frame->function(), this);
         Handle<Code> code = handle(exit_frame->LookupCode(), this);
         int offset =
             static_cast<int>(exit_frame->pc() - code->instruction_start());
 
-        // For now, builtin exit frames do not pass along a receiver.
+        // In order to help CallSite::IsConstructor detect builtin constructors,
+        // we reuse the receiver field to pass along a special symbol.
+        Handle<Object> recv;
+        if (exit_frame->IsConstructor()) {
+          recv = handle(heap()->call_site_constructor_symbol(), this);
+        } else {
+          recv = handle(exit_frame->receiver(), this);
+        }
+
         elements = MaybeGrow(this, elements, cursor, cursor + 4);
-        elements->set(cursor++, *factory()->undefined_value());
+        elements->set(cursor++, *recv);
         elements->set(cursor++, *fun);
         elements->set(cursor++, *code);
         elements->set(cursor++, Smi::FromInt(offset));
         frames_seen++;
       } break;
 
       case StackFrame::WASM: {
         WasmFrame* wasm_frame = WasmFrame::cast(frame);
         Code* code = wasm_frame->unchecked_code();
         Handle<AbstractCode> abstract_code =
@@ skipping 2629 matching lines @@
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8