[graph-builder] Fix parameter index access in VisitSuspendGenerator

The second argument of FromParameterIndex should be the parameter count, including the receiver.

Previously it worked by chance, because the code was trying to access the receiver but did not include it in the parameter count, accessing the first argument. This does not work anymore when the arguments are reversed (V8_REVERSE_JSARGS).

Change-Id: I8ca9054a99d074c130f9a9b444e7b8a379840991
Bug: v8:10201
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2282531Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68742}

src/compiler/bytecode-graph-builder.cc

@@ -3623,8 +3623,7 @@ void BytecodeGraphBuilder::VisitSuspendGenerator() {
   // Store the parameters.
   for (int i = 0; i < parameter_count_without_receiver; i++) {
     value_inputs[3 + count_written++] =
-        environment()->LookupRegister(interpreter::Register::FromParameterIndex(
-            i, parameter_count_without_receiver));
+        environment()->LookupRegister(bytecode_iterator().GetParameter(i));
   }
 
   // Store the registers.

src/interpreter/bytecode-array-accessor.cc

@@ -190,6 +190,18 @@ FeedbackSlot BytecodeArrayAccessor::GetSlotOperand(int operand_index) const {
   return FeedbackVector::ToSlot(index);
 }
 
+Register BytecodeArrayAccessor::GetReceiver() const {
+  return Register::FromParameterIndex(0, bytecode_array()->parameter_count());
+}
+
+Register BytecodeArrayAccessor::GetParameter(int parameter_index) const {
+  DCHECK_GE(parameter_index, 0);
+  // The parameter indices are shifted by 1 (receiver is the
+  // first entry).
+  return Register::FromParameterIndex(parameter_index + 1,
+                                      bytecode_array()->parameter_count());
+}
+
 Register BytecodeArrayAccessor::GetRegisterOperand(int operand_index) const {
   OperandType operand_type =
       Bytecodes::GetOperandType(current_bytecode(), operand_index);

src/interpreter/bytecode-array-accessor.h

@@ -109,6 +109,8 @@ class V8_EXPORT_PRIVATE BytecodeArrayAccessor {
   int32_t GetImmediateOperand(int operand_index) const;
   uint32_t GetIndexOperand(int operand_index) const;
   FeedbackSlot GetSlotOperand(int operand_index) const;
+  Register GetReceiver() const;
+  Register GetParameter(int parameter_index) const;
   uint32_t GetRegisterCountOperand(int operand_index) const;
   Register GetRegisterOperand(int operand_index) const;
   int GetRegisterOperandRange(int operand_index) const;