[llvm] Remove iOS 5 check for tailcalls on ARM (PR #133354)

[David Green via llvm-commits]

https://github.com/davemgreen commented:

Thanks, I've added some reviewers who might be able to say this is OK. As far as I understand it was likely disabled for older ios versions due to an issue in the linker, which likely isn't present any more?

https://github.com/llvm/llvm-project/pull/133354