[clang] [C2y] Correctly handle 0 in the preprocessor (PR #137844)

[Erich Keane via cfe-commits]

================
@@ -1420,7 +1420,7 @@ void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) {
   }
 
   // Parse a potential octal literal prefix.
-  bool SawOctalPrefix = false;
+  bool SawOctalPrefix = false, IsNakedZero = false;
----------------
erichkeane wrote:

```suggestion
  bool SawOctalPrefix = false, IsSingleZero = false;
```

https://github.com/llvm/llvm-project/pull/137844