Revert "Temporarily disable dex cache array emptyness DCHECK"

Bug: 29083330

This reverts commit 7b1541f4aecdc4c2878437ac3d46f2e74eacf0f1.
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index e789db6..fe6b14c 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -2092,8 +2092,7 @@
       reinterpret_cast<ArtMethod**>(raw_arrays + layout.MethodsOffset());
   ArtField** fields = (dex_file.NumFieldIds() == 0u) ? nullptr :
       reinterpret_cast<ArtField**>(raw_arrays + layout.FieldsOffset());
-  // Temporarily disabled since the JIT may hit this case. b/29083330
-  if (kIsDebugBuild && (false)) {
+  if (kIsDebugBuild) {
     // Sanity check to make sure all the dex cache arrays are empty. b/28992179
     for (size_t i = 0; i < dex_file.NumStringIds(); ++i) {
       CHECK(strings[i].Read<kWithoutReadBarrier>() == nullptr);