[RegisterConfiguration] Streamline access to arch defaults, simplify Registers.

src/arm/deoptimizer-arm.cc

Index: src/arm/deoptimizer-arm.cc
diff --git a/src/arm/deoptimizer-arm.cc b/src/arm/deoptimizer-arm.cc
index 3110c0a84bf18c8d2e2c1f72ab142aa73426e37a..c569e6615b097b5f5b84a0a9c0294b687844cab8 100644
--- a/src/arm/deoptimizer-arm.cc
+++ b/src/arm/deoptimizer-arm.cc
@@ -186,8 +186,7 @@ void Deoptimizer::TableEntryGenerator::Generate() {
   // Copy VFP registers to
   // double_registers_[DoubleRegister::kMaxNumAllocatableRegisters]
   int double_regs_offset = FrameDescription::double_registers_offset();
-  const RegisterConfiguration* config =
-      RegisterConfiguration::ArchDefault(RegisterConfiguration::CRANKSHAFT);
+  const RegisterConfiguration* config = RegisterConfiguration::Crankshaft();
   for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
     int code = config->GetAllocatableDoubleCode(i);
     int dst_offset = code * kDoubleSize + double_regs_offset;