Config double register number as 1 for X87 Turbofan.

src/ppc/assembler-ppc.h

Index: src/ppc/assembler-ppc.h
diff --git a/src/ppc/assembler-ppc.h b/src/ppc/assembler-ppc.h
index fb56852bb5b5c254d82662f910f0b1c5265f90dc..61fb4cad90ec7ddf3600f2d8d2357c912dcb39d8 100644
--- a/src/ppc/assembler-ppc.h
+++ b/src/ppc/assembler-ppc.h
@@ -318,6 +318,14 @@ struct DoubleRegister {
     return NumAllocatableRegisters();
   }
 
+  static int NumAllocatableRegistersForTurbo() {
+    return kMaxNumAllocatableRegisters;
+  }
+
+  static int NumAllocatableAliasedRegistersForTurbo() {
+    return NumAllocatableAliasedRegisters();
+  }
+
   static int ToAllocationIndex(DoubleRegister reg) {
     int code = reg.code();
     int index = (code <= kAllocatableLowRangeEnd)