ARM: Fix double use of IP when storing object fields with large offsets.

runtime/vm/assembler_arm.cc

Index: runtime/vm/assembler_arm.cc
diff --git a/runtime/vm/assembler_arm.cc b/runtime/vm/assembler_arm.cc
index 31824b1a8484a323c3a1130b7da93fba372e11c3..2b59966978a8094e93ec5a930ba3796b87f4d89a 100644
--- a/runtime/vm/assembler_arm.cc
+++ b/runtime/vm/assembler_arm.cc
@@ -1908,8 +1908,11 @@ void Assembler::StoreIntoObjectNoBarrierOffset(Register object,
     StoreIntoObjectNoBarrier(object, FieldAddress(object, offset), value,
                              old_content);
   } else {
-    AddImmediate(IP, object, offset - kHeapObjectTag);
-    StoreIntoObjectNoBarrier(object, Address(IP), value, old_content);
+    ASSERT(object != R9);

[Florian Schneider, 2015/11/04 20:58:01]

Not sure if this is always guaranteed: I think you need to add code to support
object == R9.

+    Push(R9);
+    AddImmediate(R9, object, offset - kHeapObjectTag);
+    StoreIntoObjectNoBarrier(object, Address(R9), value, old_content);
+    Pop(R9);
   }
 }