[llvm] [IndVarSimplify] Add safety check for getTruncateExpr in genLoopLimit (PR #172234)

[Nikita Popov via llvm-commits]

https://github.com/nikic approved this pull request.

LGTM, I think this is the best workaround for this issue for now.

https://github.com/llvm/llvm-project/pull/172234