[clang] [llvm] Enable fexec-charset option (PR #138895)

[Abhina Sree via cfe-commits]

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@@ -1842,23 +1859,52 @@ CharLiteralParser::CharLiteralParser(const char *begin, const char *end,
             HadError = true;
             PP.Diag(Loc, diag::err_character_too_large);
           }
+          if (!HadError && Converter) {
+            assert(Kind != tok::wide_char_constant &&
+                   "Wide character translation not supported");
+            char ByteChar = *tmp_out_start;
+            SmallString<1> ConvertedChar;
+            Converter->convert(StringRef(&ByteChar, 1), ConvertedChar);
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abhina-sree wrote:

Thanks, I've added proper diagnostics here now

https://github.com/llvm/llvm-project/pull/138895