[compiler-rt] [llvm] [cpp23] Remove usage of std::aligned_union<> in llvm (PR #135146)

[Jakub Kuderski via llvm-commits]

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@@ -367,8 +367,8 @@ template <typename T> class ORC_RT_NODISCARD Expected {
   }
 
   union {
-    std::aligned_union_t<1, storage_type> TStorage;
-    std::aligned_union_t<1, error_type> ErrorStorage;
+    alignas(storage_type) char TStorage[sizeof(storage_type)];
+    alignas(error_type) char ErrorStorage[sizeof(error_type)];
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kuhar wrote:

We have a bunch of existing llvm code that uses `char`, e.g.: https://github.com/llvm/llvm-project/blob/4244a91be268111dd133fa4863504c4840e5361c/llvm/include/llvm/Support/TrailingObjects.h#L355

https://github.com/llvm/llvm-project/pull/135146