[clang] [clang] Implement C2y stdc_memreverse8 and stdc_memreverse8u{8,16,32,64} builtins (PR #197358)

[Aaron Ballman via cfe-commits]

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@@ -34,6 +34,10 @@ class IntBitUtilTemplate : Template<
      "unsigned long int", "unsigned long long int"],
     ["_uc", "_us", "_ui", "_ul", "_ull"]>;
 
+class MemReverse8Template : Template<
+    ["unsigned char", "unsigned short", "uint32_t", "uint64_t"],
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AaronBallman wrote:

It's a bit interesting to see `uint32_t` but `unsigned char` instead of `uint8_t`, do we not support the smaller bit widths here?

https://github.com/llvm/llvm-project/pull/197358