Re-reland: Remove register index/code indirection

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

Index: test/cctest/test-code-stubs-arm.cc
diff --git a/test/cctest/test-code-stubs-arm.cc b/test/cctest/test-code-stubs-arm.cc
index a9856f5245be031a10ccf121a966b1ac178d99ec..385718f486c9cd037c03b2cb4fd56d35029e0373 100644
--- a/test/cctest/test-code-stubs-arm.cc
+++ b/test/cctest/test-code-stubs-arm.cc
@@ -76,11 +76,13 @@ ConvertDToIFunc MakeConvertDToIFuncTrampoline(Isolate* isolate,
   // Save registers make sure they don't get clobbered.
   int source_reg_offset = kDoubleSize;
   int reg_num = 0;
-  for (; reg_num < Register::NumAllocatableRegisters(); ++reg_num) {
+  for (; reg_num < Register::kNumRegisters; ++reg_num) {
     Register reg = Register::from_code(reg_num);
-    if (!reg.is(destination_reg)) {
-      __ push(reg);
-      source_reg_offset += kPointerSize;
+    if (reg.IsAllocatable()) {
+      if (!reg.is(destination_reg)) {
+        __ push(reg);
+        source_reg_offset += kPointerSize;
+      }
     }
   }
 
@@ -105,11 +107,13 @@ ConvertDToIFunc MakeConvertDToIFuncTrampoline(Isolate* isolate,
   // Make sure no registers have been unexpectedly clobbered
   for (--reg_num; reg_num >= 0; --reg_num) {
     Register reg = Register::from_code(reg_num);
-    if (!reg.is(destination_reg)) {
-      __ ldr(ip, MemOperand(sp, 0));
-      __ cmp(reg, ip);
-      __ Assert(eq, kRegisterWasClobbered);
-      __ add(sp, sp, Operand(kPointerSize));
+    if (reg.IsAllocatable()) {
+      if (!reg.is(destination_reg)) {
+        __ ldr(ip, MemOperand(sp, 0));
+        __ cmp(reg, ip);
+        __ Assert(eq, kRegisterWasClobbered);
+        __ add(sp, sp, Operand(kPointerSize));
+      }
     }
   }