[llvm] [SimplifyLibCalls] Simplify cabs libcall if real or imaginary part of input is zero (PR #97976)

[Hendrik Hübner via llvm-commits]

HendrikHuebner wrote:

@dtcxzyw I just noticed another mistake I made, I did not handle array type inputs correctly. If Op has type "ArrayTy", how can I get the first and second element and check if one is zero? In the existing code, IRBuilderBase.createExtractValue is used, but I can't use this to check for zeros because it actually modifies the IR and which should not happen in case there is no zero. 

https://github.com/llvm/llvm-project/pull/97976