[llvm] [GlobalISel][AArch64] Legalize G_FABS and G_FNEG for SVE (PR #114784)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

We (the IRTranslator) blindly translate `fneg` from LLVM-IR into G_FNEG. We state `def : GINodeEquiv<G_FNEG, fneg>;
`. I believe there is not much space than adding fneg patterns.

https://github.com/llvm/llvm-project/pull/114784