Remove ArtMethod* parameter from dex cache entry points.

Load the ArtMethod* using an optimized stack walk instead.
This reduces the size of the generated code.

Three of the entry points are called only from a slow-path
and the fourth (InitializeTypeAndVerifyAccess) is rare and
already slow enough that the one or two extra loads
(depending on whether we already have the ArtMethod* in a
register) are insignificant. And as we're starting to use
PC-relative addressing of the dex cache arrays (already
done by Quick for the boot image), having the ArtMethod* in
a register becomes less likely anyway.

Change-Id: Ib19b9d204e355e13bf386662a8b158178bf8ad28