[turbofan] Add TruncateFloat64ToInt32 machine operator.

src/compiler/arm64/code-generator-arm64.cc

 // Copyright 2014 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.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/arm64/macro-assembler-arm64.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 131 matching lines @@
       break;
     case kArchDeoptimize: {
       int deoptimization_id = MiscField::decode(instr->opcode());
       BuildTranslation(instr, deoptimization_id);
 
       Address deopt_entry = Deoptimizer::GetDeoptimizationEntry(
           isolate(), deoptimization_id, Deoptimizer::LAZY);
       __ Call(deopt_entry, RelocInfo::RUNTIME_ENTRY);
       break;
     }
+    case kArchTruncateDoubleToI:
+      __ TruncateDoubleToI(i.OutputRegister(), i.InputDoubleRegister(0));
+      break;
     case kArm64Add:
       __ Add(i.OutputRegister(), i.InputRegister(0), i.InputOperand(1));
       break;
     case kArm64Add32:
       if (FlagsModeField::decode(opcode) != kFlags_none) {
         __ Adds(i.OutputRegister32(), i.InputRegister32(0),
                 i.InputOperand32(1));
       } else {
         __ Add(i.OutputRegister32(), i.InputRegister32(0), i.InputOperand32(1));
       }
@@ skipping 670 matching lines @@
 }
 
 
 void CodeGenerator::AddNopForSmiCodeInlining() { __ movz(xzr, 0); }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8