ARM64: Introduce TempDoubleRegister as a lithium operand constraint.

src/arm64/lithium-arm64.h

 // Copyright 2013 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_ARM64_LITHIUM_ARM64_H_
 #define V8_ARM64_LITHIUM_ARM64_H_
 
 #include "hydrogen.h"
 #include "lithium-allocator.h"
 #include "lithium.h"
@@ skipping 3025 matching lines @@
   // A constant operand.
   MUST_USE_RESULT LConstantOperand* UseConstant(HValue* value);
 
   // An input operand in register, stack slot or a constant operand.
   // Will not be moved to a register even if one is freely available.
   virtual MUST_USE_RESULT LOperand* UseAny(HValue* value);
 
   // Temporary operand that must be in a register.
   MUST_USE_RESULT LUnallocated* TempRegister();
 
+  // Temporary operand that must be in a double register.
+  MUST_USE_RESULT LUnallocated* TempDoubleRegister();
+
   // Temporary operand that must be in a fixed double register.
   MUST_USE_RESULT LOperand* FixedTemp(DoubleRegister reg);
 
   // Methods for setting up define-use relationships.
   // Return the same instruction that they are passed.
   LInstruction* Define(LTemplateResultInstruction<1>* instr,
                        LUnallocated* result);
   LInstruction* DefineAsRegister(LTemplateResultInstruction<1>* instr);
   LInstruction* DefineAsSpilled(LTemplateResultInstruction<1>* instr,
                                 int index);
@@ skipping 36 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM64_LITHIUM_ARM64_H_