Refactor java.lang.reflect implementation

Cherry-picked from commit ed41d5c44299ec5d44b8514f6e17f802f48094d1.

Move to ArtMethod/Field instead of AbstractMethod/Field and have
java.lang.reflect APIs delegate to ArtMethod/ArtField.

Bug: 10014286.

Change-Id: Iafc1d8c5b62562c9af8fb9fd8c5e1d61270536e7
diff --git a/runtime/monitor_android.cc b/runtime/monitor_android.cc
index 9265cd6..8efa072 100644
--- a/runtime/monitor_android.cc
+++ b/runtime/monitor_android.cc
@@ -78,7 +78,7 @@
 
   // Emit the source code file name, <= 37 bytes.
   uint32_t pc;
-  mirror::AbstractMethod* m = self->GetCurrentMethod(&pc);
+  mirror::ArtMethod* m = self->GetCurrentMethod(&pc);
   const char* filename;
   uint32_t line_number;
   TranslateLocation(m, pc, filename, line_number);