[llvm] [Targets] Migrate from atomic_load_8/16/32/64 to atomic_load_nonext_8/16/32/64. NFC (PR #137428)

[Sergei Barannikov via llvm-commits]

s-barannikov wrote:

This is more question to #137401 which I slept through. Why do we need to spell out `_nonext`? It seems to be implied by *non-atomic* loads. Are atomic loads somewhat different in this regard?


https://github.com/llvm/llvm-project/pull/137428