[clang] [llvm] [ARM] Armv8-R does not require fp64 or neon. (PR #88287)

[Chris Copeland via llvm-commits]

chrisnc wrote:

@smithp35 thanks! Yes, I iterated on the specific direction here after the feedback about not changing the behavior of `-mcpu=cortex-r52`, but the first comment in the thread reflects the initial state, so I'll change that. I believe the cortex-r82 is AArch64-only, and so is not relevant here except w.r.t. consistency. I'm not familiar with how default CPUs are set in AArch64, but experimentally, `--target=aarch64-none-elf -march=armv8-r` does not generate the same code on a simple example as using `--target=aarch64-none-elf -march=cortex-r82` currently, so it does not appear to be a default there, either. Other than that, I confirm that what you've written is in line with what this change is doing.

https://github.com/llvm/llvm-project/pull/88287