PPC: Remove register index/code indirection

src/ppc/lithium-ppc.cc

Index: src/ppc/lithium-ppc.cc
diff --git a/src/ppc/lithium-ppc.cc b/src/ppc/lithium-ppc.cc
index 767c771fb31fa83eaa5b2356ab1710ed7d9262cb..09b397612f4bd512e759246cbe9ceb6bc6b1d64b 100644
--- a/src/ppc/lithium-ppc.cc
+++ b/src/ppc/lithium-ppc.cc
@@ -457,14 +457,13 @@ LPlatformChunk* LChunkBuilder::Build() {
 
 
 LUnallocated* LChunkBuilder::ToUnallocated(Register reg) {
-  return new (zone()) LUnallocated(LUnallocated::FIXED_REGISTER,
-                                   Register::ToAllocationIndex(reg));
+  return new (zone()) LUnallocated(LUnallocated::FIXED_REGISTER, reg.code());
 }
 
 
 LUnallocated* LChunkBuilder::ToUnallocated(DoubleRegister reg) {
-  return new (zone()) LUnallocated(LUnallocated::FIXED_DOUBLE_REGISTER,
-                                   DoubleRegister::ToAllocationIndex(reg));
+  return new (zone())
+      LUnallocated(LUnallocated::FIXED_DOUBLE_REGISTER, reg.code());
 }