[ValueTracking] A value is never undef or poison if it must raise UB

[ValueTracking] A value is never undef or poison if it must raise UB

Summary:
This patch helps isGuaranteedNotToBeUndefOrPoison return true if the value
makes the program always undefined.

According to value tracking functions' comments, it is not still in consensus
whether a poison value can be bitwise or not, so conservatively only the case with
i1 is considered.

Reviewers: spatel, lebedev.ri, reames, nlopes, regehr

Reviewed By: nlopes

Subscribers: uenoku, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75396