Fix AccessArgumentsAt on ARM. Use register for index.

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index 30f9bb7a1d0360d64173353feb6018f34d6eba4d..c1f24c9ec64c410b601d097e267f8961bf1819e8 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -2485,7 +2485,7 @@ LInstruction* LChunkBuilder::DoAccessArgumentsAt(HAccessArgumentsAt* instr) {
     index = UseOrConstant(instr->index());
   } else {
     length = UseTempRegister(instr->length());
-    index = Use(instr->index());
+    index = UseRegisterAtStart(instr->index());
   }
   return DefineAsRegister(new(zone()) LAccessArgumentsAt(args, length, index));
 }