Revert^3 "VIXL simulator for ART (Stage1)"

This reverts commit e886d68b9c40c941d8966b9c90d0e265c75fb19e.

Reason for revert: simulator implemention is not ready yet.

Test: lunch aosp_cf_x86_phone-userdebug && m
Test: art/test.py --run-test --optimizing --host
Change-Id: I03c8c09ea348205b0238d7a26caef3477cd6ae3b
diff --git a/compiler/optimizing/codegen_test_utils.h b/compiler/optimizing/codegen_test_utils.h
index f873e75..9d15f1f 100644
--- a/compiler/optimizing/codegen_test_utils.h
+++ b/compiler/optimizing/codegen_test_utils.h
@@ -223,15 +223,12 @@
                                 Expected expected) {
   ASSERT_TRUE(CanExecute(target_isa)) << "Target isa is not executable.";
 
-  // Simulator cannot run without runtime, because it needs quick entrypoints.
-  if (Runtime::Current() != nullptr) {
-    // Verify on simulator.
-    CodeSimulatorContainer simulator(target_isa);
-    if (simulator.CanSimulate()) {
-      Expected result = SimulatorExecute<Expected>(simulator.Get(), f);
-      if (has_result) {
-        ASSERT_EQ(expected, result);
-      }
+  // Verify on simulator.
+  CodeSimulatorContainer simulator(target_isa);
+  if (simulator.CanSimulate()) {
+    Expected result = SimulatorExecute<Expected>(simulator.Get(), f);
+    if (has_result) {
+      ASSERT_EQ(expected, result);
     }
   }