Merge V8 at r10375: Roll to 3.6.6.17

Bug: 5688872
Change-Id: I558f9b89a15d2dcf1b62dcf9f297d4d42ca5830c
diff --git a/src/arm/macro-assembler-arm.cc b/src/arm/macro-assembler-arm.cc
index f37f310..2f68eb9 100644
--- a/src/arm/macro-assembler-arm.cc
+++ b/src/arm/macro-assembler-arm.cc
@@ -395,14 +395,14 @@
 void MacroAssembler::LoadRoot(Register destination,
                               Heap::RootListIndex index,
                               Condition cond) {
-  ldr(destination, MemOperand(roots, index << kPointerSizeLog2), cond);
+  ldr(destination, MemOperand(kRootRegister, index << kPointerSizeLog2), cond);
 }
 
 
 void MacroAssembler::StoreRoot(Register source,
                                Heap::RootListIndex index,
                                Condition cond) {
-  str(source, MemOperand(roots, index << kPointerSizeLog2), cond);
+  str(source, MemOperand(kRootRegister, index << kPointerSizeLog2), cond);
 }