[compiler-rt] [FMV][AArch64] Add initial AT_HWCAP3 / AT_HWCAP4 support (PR #161595)

[via llvm-commits]

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@@ -190,3 +190,20 @@
 #ifndef HWCAP2_CSSC
 #define HWCAP2_CSSC (1UL << 34)
 #endif
+
+// Linux and BSD values
----------------
enh-google wrote:

nit: having `// Linux` and `// BSD` on each of the four lines might be clearer?

https://github.com/llvm/llvm-project/pull/161595