Fix "Never Interpret" option for all interpreters

CL 196596 added support for an option to bypass interpretation.
However, it only covers 2 our of 3 interpreters (missing mterp).
This change moves the control up a level to the common interpreter
entry where it will take effect before we select which interpreter
to use.

Also, it corrects a somewhat academic bug in that the existing
code that assumes that (dex_pc == 0) means that we just entered a
method.  If a method's dex code internally branched to address 0,
we could issue bogus method entry events.  By moving this test up
a level, we should avoid this situation.  Note, though, that dx
would never generate this pattern, and it's hard to imagine even
hand-generated dex code that would trigger a deoptimization in this
situation.

Change-Id: I6684bbf63570e02f5b01ce423c656889a890de7d