[arm64] USE unused variables in simulator

NOTREECHECKS=true
TBR=machenbach@chromium.org

Review-Url: https://codereview.chromium.org/2754283002
Cr-Commit-Position: refs/heads/master@{#43910}

src/arm64/simulator-arm64.cc

@@ -1962,6 +1962,9 @@ void Simulator::VisitLoadStoreAcquireRelease(Instruction* instr) {
   int32_t is_not_exclusive = instr->LoadStoreXNotExclusive();
   int32_t is_load = instr->LoadStoreXLoad();
   int32_t is_pair = instr->LoadStoreXPair();
+  USE(is_acquire_release);
+  USE(is_not_exclusive);
+  USE(is_pair);
   DCHECK_NE(is_acquire_release, 0);
   DCHECK_EQ(is_not_exclusive, 0);  // Non exclusive unimplemented.
   DCHECK_EQ(is_pair, 0);           // Pair unimplemented.