ARM: Make use of d16-d31 when available.

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 42036737333877b8c3f39a0ceb43dea3457c6943..0898e2f27aca660acf626eb87ef8291031415e02 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -45,7 +45,7 @@ LOsrEntry::LOsrEntry() {
   for (int i = 0; i < Register::kNumAllocatableRegisters; ++i) {
     register_spills_[i] = NULL;
   }
-  for (int i = 0; i < DoubleRegister::kNumAllocatableRegisters; ++i) {
+  for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); ++i) {
     double_register_spills_[i] = NULL;
   }
 }