ART: Move debug-checks to runtime-debug-flags

Current slow checks:
* Class status checking in ArtMethod
* Read barrier invariant checking

Bug: 35644369
Test: m test-art-host
Change-Id: I66138a9accc601fa0fa675cf600412ad3629d28f
diff --git a/runtime/art_method.cc b/runtime/art_method.cc
index 32946ef..ac433dd 100644
--- a/runtime/art_method.cc
+++ b/runtime/art_method.cc
@@ -55,6 +55,8 @@
 extern "C" void art_quick_invoke_static_stub(ArtMethod*, uint32_t*, uint32_t, Thread*, JValue*,
                                              const char*);
 
+DEFINE_RUNTIME_DEBUG_FLAG(ArtMethod, kCheckDeclaringClassState);
+
 // Enforce that we he have the right index for runtime methods.
 static_assert(ArtMethod::kRuntimeMethodDexMethodIndex == DexFile::kDexNoIndex,
               "Wrong runtime-method dex method index");