[clang] [llvm] [BPF] Add load-acquire and store-release instructions under -mcpu=v4 (PR #108636)

[Peilin Ye via cfe-commits]

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@@ -67,6 +67,8 @@ void BPFTargetInfo::getTargetDefines(const LangOptions &Opts,
     Builder.defineMacro("__BPF_FEATURE_SDIV_SMOD");
     Builder.defineMacro("__BPF_FEATURE_GOTOL");
     Builder.defineMacro("__BPF_FEATURE_ST");
+    Builder.defineMacro("__BPF_FEATURE_LOAD_ACQUIRE");
+    Builder.defineMacro("__BPF_FEATURE_STORE_RELEASE");
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peilin-ye wrote:

> But I don't have a good name for that.

+1, but I just noticed that we need to update `clang/test/Preprocessor/bpf-predefined-macros.c`.  I'll do it in the next push.

https://github.com/llvm/llvm-project/pull/108636