[turbofan] Implemented the optional Float32RoundTruncate 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/frames-arm64.h"
 #include "src/arm64/macro-assembler-arm64.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
@@ skipping 620 matching lines @@
       break;
     case kArm64Float32RoundUp:
       __ Frintp(i.OutputFloat32Register(), i.InputFloat32Register(0));
       break;
     case kArm64Float64RoundUp:
       __ Frintp(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
     case kArm64Float64RoundTiesAway:
       __ Frinta(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
+    case kArm64Float32RoundTruncate:
+      __ Frintz(i.OutputFloat32Register(), i.InputFloat32Register(0));
+      break;
     case kArm64Float64RoundTruncate:
       __ Frintz(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
     case kArm64Float64RoundTiesEven:
       __ Frintn(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
     case kArm64Add:
       __ Add(i.OutputRegister(), i.InputOrZeroRegister64(0),
              i.InputOperand2_64(1));
       break;
@@ skipping 901 matching lines @@
       padding_size -= kInstructionSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8