verifier: Bypass monitor-{enter,exit} depth checks

Per Google Bug 61916[1], the monitor-enter and monitor-exit checks in
dex2oat are excessively strict and will reject some valid APKs, such as
WhatsApp[2].  This change attempts to relax those requirements.

[1] https://code.google.com/p/android/issues/detail?id=61916
[2] http://forum.xda-developers.com/showthread.php?t=2525044

Thanks to kitkatpurity@587aefdf15a694205b0deb1b008567cd7b18ee6e