[GlobalISel] Fix crash in applyShiftOfShiftedLogic caused by CSEMIRBuilder reuse instruction

If LogicNonShiftReg is the same to Shift1Base, and shift1 const is the same to MatchInfo.Shift2 const, CSEMIRBuilder will reuse the old shift1 when build shift2.
So, if we erase MatchInfo.Shift2 at the end, actually we remove old shift1. And it will cause crash later.

Solution for this issue is just erase it earlier to avoid the crash.

Fix #58423

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D138187