[AArch64][NEON] Add famax/famin codegen patterns (#103027)
- min(abs(a), abs(b)) -> famin(a, b), max(abs(a), abs(b))-> famax(a, b)
- Changes to LLVM
- llvm/lib/Target/AArch64InstrInfo.td
- Add pattern for NEON types
- +llvm/test/CodeGen/AArch64/aarch64-neon-faminmax.ll
- Add tests with and without +faminmax flag.
