[mips] Add missing functions due to former clean up.

Patch af608d4b https://crrev.com/c/1903969 removed some functions used on mips platform.

Original Commit Message:

  [utils] Remove unused classes and functions

  This removes dead classes and functions from utils.h.

Change-Id: I558de38370b51a3f7dd0ea9712d9c9dc47fa05a1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1909747
Auto-Submit: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64927}

src/execution/mips/simulator-mips.h

@@ -693,9 +693,26 @@ class Simulator : public SimulatorBase {
   LocalMonitor local_monitor_;
   GlobalMonitor::LinkedAddress global_monitor_thread_;
 };
+#endif  // defined(USE_SIMULATOR)
+
+template <typename T>
+int Compare(const T& a, const T& b) {
+  if (a == b)
+    return 0;
+  else if (a < b)
+    return -1;
+  else
+    return 1;
+}
+
+// Returns the negative absolute value of its argument.
+template <typename T,
+          typename = typename std::enable_if<std::is_signed<T>::value>::type>
+T Nabs(T a) {
+  return a < 0 ? a : -a;
+}
 
 }  // namespace internal
 }  // namespace v8
 
-#endif  // defined(USE_SIMULATOR)
 #endif  // V8_EXECUTION_MIPS_SIMULATOR_MIPS_H_

src/execution/mips64/simulator-mips64.h

@@ -716,9 +716,26 @@ class Simulator : public SimulatorBase {
   LocalMonitor local_monitor_;
   GlobalMonitor::LinkedAddress global_monitor_thread_;
 };
+#endif  // defined(USE_SIMULATOR)
+
+template <typename T>
+int Compare(const T& a, const T& b) {
+  if (a == b)
+    return 0;
+  else if (a < b)
+    return -1;
+  else
+    return 1;
+}
+
+// Returns the negative absolute value of its argument.
+template <typename T,
+          typename = typename std::enable_if<std::is_signed<T>::value>::type>
+T Nabs(T a) {
+  return a < 0 ? a : -a;
+}
 
 }  // namespace internal
 }  // namespace v8
 
-#endif  // defined(USE_SIMULATOR)
 #endif  // V8_EXECUTION_MIPS64_SIMULATOR_MIPS64_H_