[debugger] omit exception events for rethrown exceptions in async.

src/full-codegen/x64/full-codegen-x64.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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/ast/scopes.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 1755 matching lines @@
   STATIC_ASSERT(JSGeneratorObject::kNext < JSGeneratorObject::kReturn);
   STATIC_ASSERT(JSGeneratorObject::kThrow > JSGeneratorObject::kReturn);
   __ SmiCompare(rbx, Smi::FromInt(JSGeneratorObject::kReturn));
   __ j(less, &resume);
   __ Push(result_register());
   __ j(greater, &exception);
   EmitCreateIteratorResult(true);
   EmitUnwindAndReturn();
 
   __ bind(&exception);
-  __ CallRuntime(Runtime::kThrow);
+  __ CallRuntime(expr->rethrow_on_exception() ? Runtime::kReThrow
+                                              : Runtime::kThrow);
 
   __ bind(&suspend);
   OperandStackDepthIncrement(1);  // Not popped on this path.
   VisitForAccumulatorValue(expr->generator_object());
   DCHECK(continuation.pos() > 0 && Smi::IsValid(continuation.pos()));
   __ Move(FieldOperand(rax, JSGeneratorObject::kContinuationOffset),
           Smi::FromInt(continuation.pos()));
   __ movp(FieldOperand(rax, JSGeneratorObject::kContextOffset), rsi);
   __ movp(rcx, rsi);
   __ RecordWriteField(rax, JSGeneratorObject::kContextOffset, rcx, rdx,
@@ skipping 1871 matching lines @@
   DCHECK_EQ(
       isolate->builtins()->OnStackReplacement()->entry(),
       Assembler::target_address_at(call_target_address, unoptimized_code));
   return ON_STACK_REPLACEMENT;
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64