[llvm] [AArch64] Disable FP loads/stores when fp-armv8 not enabled (PR #77817)

[Daniel Thornburgh via llvm-commits]

mysterymath wrote:

After a bit more looking around; this has been broken for quite a while (https://github.com/llvm/llvm-project/issues/30140). This PR just makes the issue somewhat worse.

https://github.com/llvm/llvm-project/pull/77817