[clang] [llvm] [AArch64] Add support for range prefetch intrinsic (PR #170490)

[Kerry McLaughlin via cfe-commits]

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kmclaughlin-arm wrote:

The new builtins are defined after the `else` below, so they are only defined for `__ARM_64BIT_STATE`.

The builtins don't require `__ARM_PREFETCH_RANGE`, but it is there as a way to check if they are implemented which is why I added `defined(__ARM_PREFETCH_RANGE)` to the tests as well.

https://github.com/llvm/llvm-project/pull/170490