[llvm] [SCEV] Fix NSW flag propagation in getGEPExpr, getMulExpr, and getAddExpr (PR #155145)

[Sebastian Pop via llvm-commits]

sebpop wrote:

> Can you please separate out the SCEV changes into separate PRs?

Separated in 4 PRs:
https://github.com/llvm/llvm-project/pull/155266
https://github.com/llvm/llvm-project/pull/155267
https://github.com/llvm/llvm-project/pull/155268
https://github.com/llvm/llvm-project/pull/155269


https://github.com/llvm/llvm-project/pull/155145