Basic obsolete methods support

Add support for executing obsolete methods following redefinitions.
This support includes methods that have been jitted. This does not add
any additional validity checks to our redefinition functions.

Note using work-arounds to ensure 916 works pending some fixes to the
compiler, deoptimizer, or both.

Test: ./test/run-test --host 914
Test: ./test/run-test --host 915
Test: ./test/run-test --host 916
Test: mma -j40 test-art-host
Test: ART_TEST_JIT=true \
      ART_TEST_INTERPRETER=true mma -j40 test-art-host
Test: ./art/tools/run-jdwp-tests.sh --mode=host --variant=X64
Test: ./art/tools/run-jdwp-tests.sh --mode=host --variant=X64 --no-jit

Bug: 32369913
Bug: 33630159

Change-Id: I78ef95f484146f1fb93c37fc50f56575bdab2432
diff --git a/runtime/art_method.h b/runtime/art_method.h
index 3bc6f5d..83ed1db 100644
--- a/runtime/art_method.h
+++ b/runtime/art_method.h
@@ -27,6 +27,7 @@
 #include "invoke_type.h"
 #include "method_reference.h"
 #include "modifiers.h"
+#include "mirror/dex_cache.h"
 #include "mirror/object.h"
 #include "obj_ptr.h"
 #include "read_barrier_option.h"
@@ -220,6 +221,12 @@
     return !IsIntrinsic() && (GetAccessFlags() & kAccObsoleteMethod) != 0;
   }
 
+  void SetIsObsolete() {
+    // TODO We should really support redefining intrinsic if possible.
+    DCHECK(!IsIntrinsic());
+    SetAccessFlags(GetAccessFlags() | kAccObsoleteMethod);
+  }
+
   template <ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
   bool IsNative() {
     return (GetAccessFlags<kReadBarrierOption>() & kAccNative) != 0;
@@ -326,6 +333,10 @@
   ALWAYS_INLINE ArtMethod* GetDexCacheResolvedMethod(uint16_t method_index,
                                                      PointerSize pointer_size)
       REQUIRES_SHARED(Locks::mutator_lock_);
+
+  ALWAYS_INLINE mirror::StringDexCacheType* GetDexCacheStrings()
+      REQUIRES_SHARED(Locks::mutator_lock_);
+
   ALWAYS_INLINE void SetDexCacheResolvedMethod(uint16_t method_index,
                                                ArtMethod* new_method,
                                                PointerSize pointer_size)