[cpp23] Remove usage of std::aligned_union<> in llvm

[victorvianna]

std::aligned_union<> is deprecated in C++23. See more details in the linked bug.

Bug: https://crbug.com/388068052

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[llvmbot]

@llvm/pr-subscribers-llvm-adt

Author: Victor Vianna (victorvianna)

Changes

std::aligned_union<> is deprecated in C++23. See more details in the linked bug.

---

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

2 Files Affected:

• (modified) compiler-rt/lib/orc/error.h (+2-2)
• (modified) llvm/include/llvm/ADT/TrieRawHashMap.h (+1-1)

diff --git a/compiler-rt/lib/orc/error.h b/compiler-rt/lib/orc/error.h
index e64332e9ae764..28035095b692a 100644
--- a/compiler-rt/lib/orc/error.h
+++ b/compiler-rt/lib/orc/error.h
@@ -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)];
   };
 
   bool HasError : 1;
diff --git a/llvm/include/llvm/ADT/TrieRawHashMap.h b/llvm/include/llvm/ADT/TrieRawHashMap.h
index 5bfe5c9e6a0f4..e312967edeb58 100644
--- a/llvm/include/llvm/ADT/TrieRawHashMap.h
+++ b/llvm/include/llvm/ADT/TrieRawHashMap.h
@@ -72,7 +72,7 @@ class ThreadSafeTrieRawHashMapBase {
 private:
   template <class T> struct AllocValueType {
     char Base[TrieContentBaseSize];
-    std::aligned_union_t<sizeof(T), T> Content;
+    alignas(T) char Content[sizeof(T)];
   };
 
 protected:

[victorvianna]

@kuhar @frederick-vs-ja could you merge the PR?

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