X87: Re-reland: Remove register index/code indirection.

src/crankshaft/x87/lithium-x87.cc

Index: src/crankshaft/x87/lithium-x87.cc
diff --git a/src/crankshaft/x87/lithium-x87.cc b/src/crankshaft/x87/lithium-x87.cc
index ed433014f96d42ae60ba076a8a4bd57ab06c8905..7a5cdfb39102bd3a27afb899133df73f217384f3 100644
--- a/src/crankshaft/x87/lithium-x87.cc
+++ b/src/crankshaft/x87/lithium-x87.cc
@@ -482,14 +482,13 @@ 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(X87Register reg) {
-  return new (zone()) LUnallocated(LUnallocated::FIXED_DOUBLE_REGISTER,
-                                   X87Register::ToAllocationIndex(reg));
+  return new (zone())
+      LUnallocated(LUnallocated::FIXED_DOUBLE_REGISTER, reg.code());
 }