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

src/x64/deoptimizer-x64.cc

Index: src/x64/deoptimizer-x64.cc
diff --git a/src/x64/deoptimizer-x64.cc b/src/x64/deoptimizer-x64.cc
index 9d70c3236b82fc72710e85a2c8db647e579766a8..35da7a2c00c6030f1c71f6813afb34c205a38a06 100644
--- a/src/x64/deoptimizer-x64.cc
+++ b/src/x64/deoptimizer-x64.cc
@@ -116,8 +116,7 @@ void Deoptimizer::TableEntryGenerator::Generate() {
   const int kDoubleRegsSize = kDoubleSize * XMMRegister::kMaxNumRegisters;
   __ subp(rsp, Immediate(kDoubleRegsSize));
 
-  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);
     XMMRegister xmm_reg = XMMRegister::from_code(code);