Add support for nested method verifiers

Can occur in the following scenario:
MethodVerifier::Verify -> MethodVerifier::GetStaticField ->
ResolveFieldJLS ->  ThrowNoSuchFieldError -> EnsureInitialized ->
VerifyClass

Also fixed another case where we can be requested to dump for ANR
while we are suspended in one of the AllowSuspension points.

Bug: 20140397

Change-Id: Ib17f6b98954caa5d1ea1c1dcde66091cc6d11c25