[flow] VM code cleanup and fixes to instruction pointer manipulations
[flow] VM code cleanup and fixes to instruction pointer manipulations

christianparpart/x0,xzero/x0,christianparpart/x0,xzero/x0,christianparpart/x0,christianparpart/x0,xzero/x0,christianparpart/x0,christianparpart/x0,christianparpart/x0,xzero/x0,xzero/x0,xzero/x0