llvmdg: strip all values when searching globals
llvmdg: strip all values when searching globals

we stripped only casts, but we'd like to strip even
constant GEP

Signed-off-by: Marek Chalupa <a05df156a69ad59faa9af9b666ef78009594c145@gmail.com>

mchalupa/dg,mchalupa/dg,mchalupa/dg,mchalupa/dg