[cleanup] Use std::make_unsigned in favor of our own.

R=marja@chromium.org

Change-Id: I3efa9e87f985b3ccb63c89881340a0e3ec7875f0
Reviewed-on: https://chromium-review.googlesource.com/522643Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45685}

src/arm64/simulator-arm64.cc

@@ -5,6 +5,7 @@
 #include <stdlib.h>
 #include <cmath>
 #include <cstdarg>
+#include <type_traits>
 
 #if V8_TARGET_ARCH_ARM64
 
@@ -1017,7 +1018,7 @@ void Simulator::AddSubWithCarry(Instruction* instr) {
 
 template <typename T>
 T Simulator::ShiftOperand(T value, Shift shift_type, unsigned amount) {
-  typedef typename make_unsigned<T>::type unsignedT;
+  typedef typename std::make_unsigned<T>::type unsignedT;
 
   if (amount == 0) {
     return value;
@@ -2518,7 +2519,7 @@ void Simulator::DataProcessing2Source(Instruction* instr) {
     }
     case UDIV_w:
     case UDIV_x: {
-      typedef typename make_unsigned<T>::type unsignedT;
+      typedef typename std::make_unsigned<T>::type unsignedT;
       unsignedT rn = static_cast<unsignedT>(reg<T>(instr->Rn()));
       unsignedT rm = static_cast<unsignedT>(reg<T>(instr->Rm()));
       if (rm == 0) {
@@ -2623,7 +2624,7 @@ void Simulator::VisitDataProcessing3Source(Instruction* instr) {
 
 template <typename T>
 void Simulator::BitfieldHelper(Instruction* instr) {
-  typedef typename make_unsigned<T>::type unsignedT;
+  typedef typename std::make_unsigned<T>::type unsignedT;
   T reg_size = sizeof(T) * 8;
   T R = instr->ImmR();
   T S = instr->ImmS();

src/utils.h

@@ -267,25 +267,6 @@ inline int32_t WhichPowerOf2Abs(int32_t x) {
 }
 
 
-// Obtains the unsigned type corresponding to T
-// available in C++11 as std::make_unsigned
-template<typename T>
-struct make_unsigned {
-  typedef T type;
-};
-
-
-// Template specializations necessary to have make_unsigned work
-template<> struct make_unsigned<int32_t> {
-  typedef uint32_t type;
-};
-
-
-template<> struct make_unsigned<int64_t> {
-  typedef uint64_t type;
-};
-
-
 // ----------------------------------------------------------------------------
 // BitField is a help template for encoding and decode bitfield with
 // unsigned content.