[llvm] [Float2Int] Resolve FIXME: Pick the smallest legal type that fits (PR #79158)

[via llvm-commits]

alexfh wrote:

As far as clang is concerned, you can use LLVM options `-opt-bisect-limit` (https://llvm.org/docs/OptBisect.html), `-print-before-all`, `-print-after-all`, `-print-module-scope`, `-print-pipeline-passes` (all need to be prepended with `-mllvm` when passed to clang).

Apart from that, the `Opt Pipeline` view in the compiler explorer may be useful: https://godbolt.org/z/MY38Wc5dn

https://github.com/llvm/llvm-project/pull/79158