provides a mechanism for optimizing compilers to select the different Register configuration.

test/cctest/compiler/test-multiple-return.cc

Index: test/cctest/compiler/test-multiple-return.cc
diff --git a/test/cctest/compiler/test-multiple-return.cc b/test/cctest/compiler/test-multiple-return.cc
index 6fd84a9872b0cee8a715e7b6a0a4467cd1783689..a6ee1c8da7b32e67b5597d8d4a0bd96a5d663e8d 100644
--- a/test/cctest/compiler/test-multiple-return.cc
+++ b/test/cctest/compiler/test-multiple-return.cc
@@ -29,7 +29,8 @@ CallDescriptor* GetCallDescriptor(Zone* zone, int return_count,
                                   int param_count) {
   MachineSignature::Builder msig(zone, return_count, param_count);
   LocationSignature::Builder locations(zone, return_count, param_count);
-  const RegisterConfiguration* config = RegisterConfiguration::ArchDefault();
+  const RegisterConfiguration* config =
+      RegisterConfiguration::ArchDefault(RegisterConfiguration::TURBOFAN);
 
   // Add return location(s).
   DCHECK(return_count <= config->num_allocatable_general_registers());