[turbofan][arm64] Match fneg for -0.0 - x pattern.

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

Index: src/compiler/arm64/code-generator-arm64.cc
diff --git a/src/compiler/arm64/code-generator-arm64.cc b/src/compiler/arm64/code-generator-arm64.cc
index 34ec3821f7ba1605d0865c5a52414df7848dc993..56f1d9e52c38273fb900b71af8715a47d4ecd100 100644
--- a/src/compiler/arm64/code-generator-arm64.cc
+++ b/src/compiler/arm64/code-generator-arm64.cc
@@ -689,6 +689,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
                        0, 2);
       break;
     }
+    case kArm64Float64Neg:
+      __ Fneg(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
+      break;
     case kArm64Float64Sqrt:
       __ Fsqrt(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;