Revert of Reland: Remove register index/code indirection

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

Index: test/cctest/test-code-stubs-mips.cc
diff --git a/test/cctest/test-code-stubs-mips.cc b/test/cctest/test-code-stubs-mips.cc
index def09238fdff546214f54d507cc41985278c922d..10704efdcae9881e6b0cfdc839b6760502c653a0 100644
--- a/test/cctest/test-code-stubs-mips.cc
+++ b/test/cctest/test-code-stubs-mips.cc
@@ -34,7 +34,6 @@
 #include "src/factory.h"
 #include "src/macro-assembler.h"
 #include "src/mips/constants-mips.h"
-#include "src/register-configuration.h"
 #include "src/simulator.h"
 #include "test/cctest/cctest.h"
 #include "test/cctest/test-code-stubs.h"
@@ -80,13 +79,11 @@
   // Save registers make sure they don't get clobbered.
   int source_reg_offset = kDoubleSize;
   int reg_num = 2;
-  for (; reg_num < Register::kNumRegisters; ++reg_num) {
+  for (; reg_num < Register::NumAllocatableRegisters(); ++reg_num) {
     Register reg = Register::from_code(reg_num);
-    if (reg.IsAllocatable()) {
-      if (!reg.is(destination_reg)) {
-        __ push(reg);
-        source_reg_offset += kPointerSize;
-      }
+    if (!reg.is(destination_reg)) {
+      __ push(reg);
+      source_reg_offset += kPointerSize;
     }
   }