MIPS64 Fix mjsunit/compiler/reflect-construct test failure

Change-Id: I9185b17c73ad4486b81538a8ce2f84271b820919
Reviewed-on: https://chromium-review.googlesource.com/936763Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Cr-Commit-Position: refs/heads/master@{#51560}

src/builtins/mips64/builtins-mips64.cc

@@ -1640,6 +1640,7 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   Register scratch = a4;
 
   __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
+
   // 1. Load receiver into a1, argArray into a2 (if present), remove all
   // arguments from the stack (including the receiver), and push thisArg (if
   // present) instead.
@@ -1748,6 +1749,7 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
   Register scratch = a4;
 
   __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
+
   // 1. Load target into a1 (if present), argumentsList into a2 (if present),
   // remove all arguments from the stack (including the receiver), and push
   // thisArgument (if present) instead.
@@ -1802,6 +1804,8 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
   Register undefined_value = a4;
   Register scratch = a5;
 
+  __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
+
   // 1. Load target into a1 (if present), argumentsList into a2 (if present),
   // new.target into a3 (if present, otherwise use target), remove all
   // arguments from the stack (including the receiver), and push thisArgument