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

[Hubert Tong via llvm-commits]

================
@@ -101,6 +101,13 @@ inline bool isLiteral(TokenKind K) {
          isStringLiteral(K) || K == tok::header_name || K == tok::binary_data;
 }
 
+/// Return true if this is a utf literal kind.
----------------
hubert-reinterpretcast wrote:

Minor nit: Use "UTF" (all caps).
```suggestion
/// Return true if this is a UTF literal kind.
```

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