AArch64: Add suspend check in managed code.

TODO: Remove x19 in the frame in runtime, generic jni, compiled jni.

Change-Id: Ibdc292c9e7adb3a5d3eff353c22f60ffc101f549
diff --git a/compiler/dex/quick/arm64/int_arm64.cc b/compiler/dex/quick/arm64/int_arm64.cc
index 38f110e..8dad90a 100644
--- a/compiler/dex/quick/arm64/int_arm64.cc
+++ b/compiler/dex/quick/arm64/int_arm64.cc
@@ -725,17 +725,10 @@
 
 // Test suspend flag, return target of taken suspend branch
 LIR* Arm64Mir2Lir::OpTestSuspend(LIR* target) {
-  // TODO(Arm64): re-enable suspend checks, once art_quick_test_suspend is implemented and
-  //   the suspend register is properly handled in the trampolines.
-#if 0
+  // FIXME: Define rA64_SUSPEND as w19, when we do not need two copies of reserved register.
+  // Note: The opcode is not set as wide, so actually we are using the 32-bit version register.
   NewLIR3(kA64Subs3rRd, rA64_SUSPEND, rA64_SUSPEND, 1);
   return OpCondBranch((target == NULL) ? kCondEq : kCondNe, target);
-#else
-  // TODO(Arm64): Fake suspend check. Will always fail to branch. Remove this.
-  LIR* branch = NewLIR2((target == NULL) ? kA64Cbnz2rt : kA64Cbz2rt, rwzr, 0);
-  branch->target = target;
-  return branch;
-#endif
 }
 
 // Decrement register and branch on condition