[clang-tools-extra] [clangd] Correctly identify the next token after the completion point (PR #69153)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

I've no idea what the error causing the format check ("Error: Unable to determine a difference between 8592241e29e29f0e7e407e0989489c6e70c91c42..e1ae800faed2fe3f612686edf6fe61f5b16e090d") to fail means.

https://github.com/llvm/llvm-project/pull/69153