[turbofan] Revive the VectorSlotPair and also put feedback on JSCallFunction.

src/utils.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_UTILS_H_
 #define V8_UTILS_H_
 
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 1029 matching lines @@
   static const int kNoneId = -1;
 
   int id_;
 };
 
 
 template <int dummy_parameter>
 class VectorSlot {
  public:
   explicit VectorSlot(int id) : id_(id) {}
+
   int ToInt() const { return id_; }
 
   static VectorSlot Invalid() { return VectorSlot(kInvalidSlot); }
   bool IsInvalid() const { return id_ == kInvalidSlot; }
 
   VectorSlot next() const {
-    DCHECK(id_ != kInvalidSlot);
+    DCHECK_NE(kInvalidSlot, id_);
     return VectorSlot(id_ + 1);
   }
 
-  bool operator==(const VectorSlot& other) const { return id_ == other.id_; }
+  bool operator==(VectorSlot that) const { return this->id_ == that.id_; }
+  bool operator!=(VectorSlot that) const { return !(*this == that); }
 
  private:
   static const int kInvalidSlot = -1;
 
   int id_;
 };
 
 
+template <int dummy_parameter>
+size_t hash_value(VectorSlot<dummy_parameter> slot) {
+  return slot.ToInt();
+}
+
+
 typedef VectorSlot<0> FeedbackVectorSlot;
 typedef VectorSlot<1> FeedbackVectorICSlot;
 
 
 class BailoutId {
  public:
   explicit BailoutId(int id) : id_(id) { }
   int ToInt() const { return id_; }
 
   static BailoutId None() { return BailoutId(kNoneId); }
@@ skipping 661 matching lines @@
   uint32_t* ptr = reinterpret_cast<uint32_t*>(p);
   *ptr = c.u[0];
   *(ptr + 1) = c.u[1];
 #endif  // V8_TARGET_ARCH_MIPS
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_UTILS_H_