[clang] [clang] Bounds checking on unclosed parentheses, brackets or braces in Expanded Tokens (PR #69849)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

Superseded by #78092.

Thanks for putting together this patch, @robozati. While we didn't go with the fix approach taken in this patch, it did prod me to look at the issue in more detail :laughing: 

https://github.com/llvm/llvm-project/pull/69849