ART: Fix deopt from optimized code under inlining

Deoptimization of inlined frames would use the outer method's
vreg map, thus starting interpreter in bogus state.

Bug: 25331616
Change-Id: I1d4aefc731bb1386f3e6186a89b59981836480b3
diff --git a/runtime/stack.h b/runtime/stack.h
index 1276b24..aa7b616 100644
--- a/runtime/stack.h
+++ b/runtime/stack.h
@@ -698,6 +698,10 @@
     return current_inlining_depth_ != 0;
   }
 
+  size_t GetCurrentInliningDepth() const {
+    return current_inlining_depth_;
+  }
+
   uintptr_t GetCurrentQuickFramePc() const {
     return cur_quick_frame_pc_;
   }