[llvm] [Reland][ValueTracking] Improve Bitcast handling to match SDAG (PR #145223)

[Abhishek Kaushik via llvm-commits]

abhishek-kaushik22 wrote:

> Can you please add a test for a case that was previously miscompiled?

I'm trying to reduce [this](https://[martin.st/temp/loopfilter_sse2-preproc.c](https://martin.st/temp/loopfilter_sse2-preproc.c)), I'm not sure what the miscompile was

https://github.com/llvm/llvm-project/pull/145223