[turbofan] Enable DivIsSafe flag for arm64.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/773803003

Cr-Commit-Position: refs/heads/master@{#25623}

src/compiler/arm64/instruction-selector-arm64.cc

@@ -1528,7 +1528,9 @@ InstructionSelector::SupportedMachineOperatorFlags() {
          MachineOperatorBuilder::kFloat64Ceil |
          MachineOperatorBuilder::kFloat64RoundTruncate |
          MachineOperatorBuilder::kFloat64RoundTiesAway |
-         MachineOperatorBuilder::kWord32ShiftIsSafe;
+         MachineOperatorBuilder::kWord32ShiftIsSafe |
+         MachineOperatorBuilder::kInt32DivIsSafe |
+         MachineOperatorBuilder::kUint32DivIsSafe;
 }
 }  // namespace compiler
 }  // namespace internal