VM-codegen: Clean up the way we emit code for comparison instructions.

runtime/vm/constants_arm64.h

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_CONSTANTS_ARM64_H_
 #define RUNTIME_VM_CONSTANTS_ARM64_H_
 
 #include "platform/assert.h"
 
 namespace dart {
@@ skipping 175 matching lines @@
   VS = 6,   // overflow
   VC = 7,   // no overflow
   HI = 8,   // unsigned higher
   LS = 9,   // unsigned lower or same
   GE = 10,  // signed greater than or equal
   LT = 11,  // signed less than
   GT = 12,  // signed greater than
   LE = 13,  // signed less than or equal
   AL = 14,  // always (unconditional)
   NV = 15,  // special condition (refer to section C1.2.3)
-  kMaxCondition = 16,
+  kNumberOfConditions = 16,
+  kInvalidCondition = 16
 };
 
 static inline Condition InvertCondition(Condition c) {
   const int32_t i = static_cast<int32_t>(c) ^ 0x1;
   return static_cast<Condition>(i);
 }
 
 enum Bits {
   B0 = (1 << 0),
   B1 = (1 << 1),
@@ skipping 918 matching lines @@
   static Instr* At(uword pc) { return reinterpret_cast<Instr*>(pc); }
 
  private:
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(Instr);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_CONSTANTS_ARM64_H_