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

src/mips/deoptimizer-mips.cc

Index: src/mips/deoptimizer-mips.cc
diff --git a/src/mips/deoptimizer-mips.cc b/src/mips/deoptimizer-mips.cc
index e9caaadadbcbd257fd0f1bf642a6b0cb875c5563..478b9dfe30ec20ac2307184c69aedcc202041a56 100644
--- a/src/mips/deoptimizer-mips.cc
+++ b/src/mips/deoptimizer-mips.cc
@@ -117,8 +117,7 @@ void Deoptimizer::TableEntryGenerator::Generate() {
 
   // Save all FPU registers before messing with them.
   __ Subu(sp, sp, Operand(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);
     const DoubleRegister fpu_reg = DoubleRegister::from_code(code);