Re-reland: Remove register index/code indirection

src/x87/assembler-x87.h

Index: src/x87/assembler-x87.h
diff --git a/src/x87/assembler-x87.h b/src/x87/assembler-x87.h
index 1f454bcd9023275bc8a8e0e7ccaeaf10a119b33b..a2a90dfc3ccd764b8c8b5a6a17c04fa897825d3e 100644
--- a/src/x87/assembler-x87.h
+++ b/src/x87/assembler-x87.h
@@ -76,10 +76,6 @@ struct Register {
 
   static inline const char* AllocationIndexToString(int index);
 
-  static inline int ToAllocationIndex(Register reg);
-
-  static inline Register FromAllocationIndex(int index);
-
   static Register from_code(int code) {
     DCHECK(code >= 0);
     DCHECK(code < kNumRegisters);
@@ -132,18 +128,6 @@ inline const char* Register::AllocationIndexToString(int index) {
 }
 
 
-inline int Register::ToAllocationIndex(Register reg) {
-  DCHECK(reg.is_valid() && !reg.is(esp) && !reg.is(ebp));
-  return (reg.code() >= 6) ? reg.code() - 2 : reg.code();
-}
-
-
-inline Register Register::FromAllocationIndex(int index)  {
-  DCHECK(index >= 0 && index < kMaxNumAllocatableRegisters);
-  return (index >= 4) ? from_code(index + 2) : from_code(index);
-}
-
-
 struct X87Register {
   static const int kMaxNumAllocatableRegisters = 6;
   static const int kMaxNumRegisters = 8;