Improved instruction + offset hunting.

Rationale:
This is generally useful for anything using this method
but in particular for deopting something like

 bs[  off] = (byte)(n >>> 24);
 bs[++off] = (byte)(n >>> 16);
 bs[++off] = (byte)(n >>>  8);
 bs[++off] = (byte)(n       );

where the base + offset is hidden in the increments.
Occurs quite often in real-life code.

Change-Id: I3fa7d285a7368a179a26e590e8eee37f3b64c25d