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

src/s390/macro-assembler-s390.cc

Index: src/s390/macro-assembler-s390.cc
diff --git a/src/s390/macro-assembler-s390.cc b/src/s390/macro-assembler-s390.cc
index 9d62387c855502d0089c6e6342fab35b76acfc9c..ca48614cc4190d443163de00a790b2227a67ec42 100644
--- a/src/s390/macro-assembler-s390.cc
+++ b/src/s390/macro-assembler-s390.cc
@@ -637,8 +637,7 @@ MemOperand MacroAssembler::SafepointRegisterSlot(Register reg) {
 
 MemOperand MacroAssembler::SafepointRegistersAndDoublesSlot(Register reg) {
   // General purpose registers are pushed last on the stack.
-  const RegisterConfiguration* config =
-      RegisterConfiguration::ArchDefault(RegisterConfiguration::CRANKSHAFT);
+  const RegisterConfiguration* config = RegisterConfiguration::Crankshaft();
   int doubles_size = config->num_allocatable_double_registers() * kDoubleSize;
   int register_offset = SafepointRegisterStackIndex(reg.code()) * kPointerSize;
   return MemOperand(sp, doubles_size + register_offset);
@@ -3697,8 +3696,7 @@ Register GetRegisterThatIsNotOneOf(Register reg1, Register reg2, Register reg3,
   if (reg5.is_valid()) regs |= reg5.bit();
   if (reg6.is_valid()) regs |= reg6.bit();
 
-  const RegisterConfiguration* config =
-      RegisterConfiguration::ArchDefault(RegisterConfiguration::CRANKSHAFT);
+  const RegisterConfiguration* config = RegisterConfiguration::Crankshaft();
   for (int i = 0; i < config->num_allocatable_general_registers(); ++i) {
     int code = config->GetAllocatableGeneralCode(i);
     Register candidate = Register::from_code(code);