Leaving a generator via an exception causes it to close

src/arm64/full-codegen-arm64.cc

Index: src/arm64/full-codegen-arm64.cc
diff --git a/src/arm64/full-codegen-arm64.cc b/src/arm64/full-codegen-arm64.cc
index b693d591270457c022d1f84aff55bd7cbea899fa..bc20733e3efe16edc9ef813d253e3948c4ad60a4 100644
--- a/src/arm64/full-codegen-arm64.cc
+++ b/src/arm64/full-codegen-arm64.cc
@@ -4933,7 +4933,6 @@ void FullCodeGenerator::EmitGeneratorResume(Expression *generator,
     Expression *value,
     JSGeneratorObject::ResumeMode resume_mode) {
   ASM_LOCATION("FullCodeGenerator::EmitGeneratorResume");
-  Register value_reg = x0;
   Register generator_object = x1;
   Register the_hole = x2;
   Register operand_stack_size = w3;
@@ -4947,15 +4946,6 @@ void FullCodeGenerator::EmitGeneratorResume(Expression *generator,
   VisitForAccumulatorValue(value);
   __ Pop(generator_object);
 
-  // Check generator state.
-  Label wrong_state, closed_state, done;
-  __ Ldr(x10, FieldMemOperand(generator_object,
-                              JSGeneratorObject::kContinuationOffset));
-  STATIC_ASSERT(JSGeneratorObject::kGeneratorExecuting < 0);
-  STATIC_ASSERT(JSGeneratorObject::kGeneratorClosed == 0);
-  __ CompareAndBranch(x10, Smi::FromInt(0), eq, &closed_state);
-  __ CompareAndBranch(x10, Smi::FromInt(0), lt, &wrong_state);
-
   // Load suspended function and context.
   __ Ldr(cp, FieldMemOperand(generator_object,
                              JSGeneratorObject::kContextOffset));
@@ -4981,7 +4971,7 @@ void FullCodeGenerator::EmitGeneratorResume(Expression *generator,
 
   // Enter a new JavaScript frame, and initialize its slots as they were when
   // the generator was suspended.
-  Label resume_frame;
+  Label resume_frame, done;
   __ Bl(&resume_frame);
   __ B(&done);
 
@@ -5026,26 +5016,6 @@ void FullCodeGenerator::EmitGeneratorResume(Expression *generator,
   // Not reached: the runtime call returns elsewhere.
   __ Unreachable();
 
-  // Reach here when generator is closed.
-  __ Bind(&closed_state);
-  if (resume_mode == JSGeneratorObject::NEXT) {
-    // Return completed iterator result when generator is closed.
-    __ LoadRoot(x10, Heap::kUndefinedValueRootIndex);
-    __ Push(x10);
-    // Pop value from top-of-stack slot; box result into result register.
-    EmitCreateIteratorResult(true);
-  } else {
-    // Throw the provided value.
-    __ Push(value_reg);
-    __ CallRuntime(Runtime::kThrow, 1);
-  }
-  __ B(&done);
-
-  // Throw error if we attempt to operate on a running generator.
-  __ Bind(&wrong_state);
-  __ Push(generator_object);
-  __ CallRuntime(Runtime::kThrowGeneratorStateError, 1);
-
   __ Bind(&done);
   context()->Plug(result_register());
 }