Simplify Hydrogen code stubs with variable argument count

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index 2607f9eac2e1b59b9418a98c01c5d79b63cd5348..94e114fef94c69976f097a058e5067b6365b6dd6 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -189,14 +189,21 @@ static void InitializeArrayConstructorDescriptor(
   // r0 -- number of arguments
   // r1 -- function
   // r2 -- type info cell with elements kind
-  static Register registers[] = { r1, r2 };
-  descriptor->register_param_count_ = 2;
-  if (constant_stack_parameter_count != 0) {
+  static Register registers_variable_args[] = { r1, r2, r0 };
+  static Register registers_no_args[] = { r1, r2 };
+
+  if (constant_stack_parameter_count == 0) {
+    descriptor->register_param_count_ = 2;
+    descriptor->register_params_ = registers_no_args;
+  } else {
     // stack param count needs (constructor pointer, and single argument)
+    descriptor->handler_arguments_mode_ = PASS_ARGUMENTS;
     descriptor->stack_parameter_count_ = r0;
+    descriptor->register_param_count_ = 3;
+    descriptor->register_params_ = registers_variable_args;
   }
+
   descriptor->hint_stack_parameter_count_ = constant_stack_parameter_count;
-  descriptor->register_params_ = registers;
   descriptor->function_mode_ = JS_FUNCTION_STUB_MODE;
   descriptor->deoptimization_handler_ =
       Runtime::FunctionForId(Runtime::kArrayConstructor)->entry;
@@ -210,15 +217,21 @@ static void InitializeInternalArrayConstructorDescriptor(
   // register state
   // r0 -- number of arguments
   // r1 -- constructor function
-  static Register registers[] = { r1 };
-  descriptor->register_param_count_ = 1;
+  static Register registers_variable_args[] = { r1, r0 };
+  static Register registers_no_args[] = { r1 };
 
-  if (constant_stack_parameter_count != 0) {
+  if (constant_stack_parameter_count == 0) {
+    descriptor->register_param_count_ = 1;
+    descriptor->register_params_ = registers_no_args;
+  } else {
     // stack param count needs (constructor pointer, and single argument)
+    descriptor->handler_arguments_mode_ = PASS_ARGUMENTS;
     descriptor->stack_parameter_count_ = r0;
+    descriptor->register_param_count_ = 2;
+    descriptor->register_params_ = registers_variable_args;
   }
+
   descriptor->hint_stack_parameter_count_ = constant_stack_parameter_count;
-  descriptor->register_params_ = registers;
   descriptor->function_mode_ = JS_FUNCTION_STUB_MODE;
   descriptor->deoptimization_handler_ =
       Runtime::FunctionForId(Runtime::kInternalArrayConstructor)->entry;