[llvm] [X86] Truncate i64 add/sub/mul arithmetic to i32 with known zeros in upper 32 bits (PR #143313)

[Phoebe Wang via llvm-commits]

phoebewang wrote:

- Please do not clang-format the whole file. Only format the changes in the patch, see https://clang.llvm.org/docs/ClangFormat.html#script-for-patch-reformatting
- I didn't find the real change due to the noise, but the description doesn't look correct to me. We need to make sure the high 33-bits are zeros in case the carry bit error.

https://github.com/llvm/llvm-project/pull/143313