[turbofan] Remove the FloatXXSubPreserveNan operators.

test/unittests/compiler/arm64/instruction-selector-arm64-unittest.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 "test/unittests/compiler/instruction-selector-unittest.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
@@ skipping 4201 matching lines @@
   Stream s = m.Build();
   ASSERT_EQ(1U, s.size());
   EXPECT_EQ(kArm64Float64Abs, s[0]->arch_opcode());
   ASSERT_EQ(1U, s[0]->InputCount());
   EXPECT_EQ(s.ToVreg(p0), s.ToVreg(s[0]->InputAt(0)));
   ASSERT_EQ(1U, s[0]->OutputCount());
   EXPECT_EQ(s.ToVreg(n), s.ToVreg(s[0]->Output()));
 }
 
 
-TEST_F(InstructionSelectorTest, Float64SubWithMinusZero) {
-  StreamBuilder m(this, MachineType::Float64(), MachineType::Float64());
-  Node* const p0 = m.Parameter(0);
-  Node* const n = m.Float64Sub(m.Float64Constant(-0.0), p0);
-  m.Return(n);
-  Stream s = m.Build();
-  ASSERT_EQ(1U, s.size());
-  EXPECT_EQ(kArm64Float64Neg, s[0]->arch_opcode());
-  ASSERT_EQ(1U, s[0]->InputCount());
-  EXPECT_EQ(s.ToVreg(p0), s.ToVreg(s[0]->InputAt(0)));
-  ASSERT_EQ(1U, s[0]->OutputCount());
-  EXPECT_EQ(s.ToVreg(n), s.ToVreg(s[0]->Output()));
-}
-
-
 TEST_F(InstructionSelectorTest, Float64Max) {
   StreamBuilder m(this, MachineType::Float64(), MachineType::Float64(),
                   MachineType::Float64());
   Node* const p0 = m.Parameter(0);
   Node* const p1 = m.Parameter(1);
   Node* const n = m.Float64Max(p0, p1);
   m.Return(n);
   Stream s = m.Build();
   ASSERT_EQ(1U, s.size());
   EXPECT_EQ(kArm64Float64Max, s[0]->arch_opcode());
@@ skipping 48 matching lines @@
   EXPECT_EQ(kArm64Float64Neg, s[0]->arch_opcode());
   ASSERT_EQ(1U, s[0]->InputCount());
   EXPECT_EQ(s.ToVreg(p0), s.ToVreg(s[0]->InputAt(0)));
   ASSERT_EQ(1U, s[0]->OutputCount());
   EXPECT_EQ(s.ToVreg(n), s.ToVreg(s[0]->Output()));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8