[clang] [llvm] [SimplifyCFG] Extend jump-threading to allow live local defs (PR #135079)

[Nikita Popov via cfe-commits]

nikic wrote:

> @nikic Can you check the compile-time impact of this patch?

https://llvm-compile-time-tracker.com/compare.php?from=aa27d4e0c3aef8047828aa453f2943730aa779c6&to=6fab608ecf50f2f36ee635e3a5d7e5f326c9e635&stat=instructions:u

https://github.com/llvm/llvm-project/pull/135079