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

test/cctest/test-code-stubs-x87.cc

Index: test/cctest/test-code-stubs-x87.cc
diff --git a/test/cctest/test-code-stubs-x87.cc b/test/cctest/test-code-stubs-x87.cc
index ef44f5420b3cab82add4634bf0c839d4f8a28e03..e0f9a453ed20fc65c8fea39f37aa47fc145efe8a 100644
--- a/test/cctest/test-code-stubs-x87.cc
+++ b/test/cctest/test-code-stubs-x87.cc
@@ -70,11 +70,13 @@ ConvertDToIFunc MakeConvertDToIFuncTrampoline(Isolate* isolate,
   int param_offset = 7 * kPointerSize;
   // Save registers make sure they don't get clobbered.
   int reg_num = 0;
-  for (; reg_num < Register::NumAllocatableRegisters(); ++reg_num) {
-    Register reg = Register::FromAllocationIndex(reg_num);
-    if (!reg.is(esp) && !reg.is(ebp) && !reg.is(destination_reg)) {
-      __ push(reg);
-      param_offset += kPointerSize;
+  for (; reg_num < Register::kNumRegisters; ++reg_num) {
+    Register reg = Register::from_code(reg_num);
+    if (reg.IsAllocatable()) {
+      if (!reg.is(esp) && !reg.is(ebp) && !reg.is(destination_reg)) {
+        __ push(reg);
+        param_offset += kPointerSize;
+      }
     }
   }
 
@@ -89,11 +91,13 @@ ConvertDToIFunc MakeConvertDToIFuncTrampoline(Isolate* isolate,
 
   // Make sure no registers have been unexpectedly clobbered
   for (--reg_num; reg_num >= 0; --reg_num) {
-    Register reg = Register::FromAllocationIndex(reg_num);
-    if (!reg.is(esp) && !reg.is(ebp) && !reg.is(destination_reg)) {
-      __ cmp(reg, MemOperand(esp, 0));
-      __ Assert(equal, kRegisterWasClobbered);
-      __ add(esp, Immediate(kPointerSize));
+    Register reg = Register::from_code(reg_num);
+    if (reg.IsAllocatable()) {
+      if (!reg.is(esp) && !reg.is(ebp) && !reg.is(destination_reg)) {
+        __ cmp(reg, MemOperand(esp, 0));
+        __ Assert(equal, kRegisterWasClobbered);
+        __ add(esp, Immediate(kPointerSize));
+      }
     }
   }