Fix index register assignment in LoadFieldByIndex for arm, arm64, and mips.

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index eb960a4bb2c06629272c6e81c19ae1a1adb69c37..e882655d21501d6cf94718cdff670f5a457ed6b2 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -2507,7 +2507,7 @@ LInstruction* LChunkBuilder::DoCheckMapValue(HCheckMapValue* instr) {
 
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
-  LOperand* index = UseRegister(instr->index());
+  LOperand* index = UseTempRegister(instr->index());
   LLoadFieldByIndex* load = new(zone()) LLoadFieldByIndex(object, index);
   LInstruction* result = DefineSameAsFirst(load);
   return AssignPointerMap(result);