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

src/compiler/pipeline.cc

Index: src/compiler/pipeline.cc
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
index a8d40cd9f7cf8da94165740afbf0e2049cd4bde9..978a2c93dc052062bc316e866fca78bc8f88dec9 100644
--- a/src/compiler/pipeline.cc
+++ b/src/compiler/pipeline.cc
@@ -1299,8 +1299,8 @@ Handle<Code> Pipeline::ScheduleAndGenerateCode(
 
   bool run_verifier = FLAG_turbo_verify_allocation;
   // Allocate registers.
-  AllocateRegisters(RegisterConfiguration::ArchDefault(), call_descriptor,
-                    run_verifier);
+  AllocateRegisters(RegisterConfiguration::ArchDefaultForTurbo(),
+                    call_descriptor, run_verifier);
   if (data->compilation_failed()) {
     info()->AbortOptimization(kNotEnoughVirtualRegistersRegalloc);
     return Handle<Code>();