[clang-tools-extra] [clang] [clangd] Handle an expanded token range that ends in the `eof` token in TokenBuffer::spelledForExpanded() (PR #78092)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

Based on previous discussion and analysis in https://github.com/llvm/llvm-project/pull/69849

https://github.com/llvm/llvm-project/pull/78092