[clang-tools-extra] [clangd] Show definition of underlying struct when hovering over a typedef (PR #89570)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

Updated patch with the following changes:

 * Decoupled from https://github.com/clangd/clangd/issues/959
 * Handle the case of multiple layers of typedefs, and add tests for this case
 * Add C language specific tests

https://github.com/llvm/llvm-project/pull/89570