[clang] [libcxx] [llvm] [Clang] Add warnings when mixing different charN_t types (PR #138708)

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@@ -618,7 +618,7 @@ template <class InternT, class ExternT>
 void utf8_to_utf16_in_error(const std::codecvt<InternT, ExternT, mbstate_t>& cvt) {
   // UTF-8 string of 1-byte CP, 2-byte CP, 3-byte CP, 4-byte CP
   const unsigned char input[] = "b\u0448\uD700\U0010AAAA";
-  const char16_t expected[]   = {'b', 0x0448, 0xD700, 0xDBEA, 0xDEAA, 0};
+  const InternT expected[]    = {0x62, 0x0448, 0xD700, 0xDBEA, 0xDEAA, 0};
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cor3ntin wrote:

These changes ('b) were a no-op, I reverted them

https://github.com/llvm/llvm-project/pull/138708