[clang] [clang][doc]: Merge the contents of identical entries. (PR #134089)

[via cfe-commits]

YLChenZ wrote:

Hi @AaronBallman, bothering you again. I have a doubt about the merge of the following case:
![屏幕截图 2025-04-04 081652](https://github.com/user-attachments/assets/ce592ae1-b02a-45bf-aece-55e3a175a01f)

There is a lot of content that is `No documentation`, and to merge these entries would be to create a very large entry, like this:
![屏幕截图 2025-04-04 082342](https://github.com/user-attachments/assets/ef047724-5ac0-4721-928f-5cae5cee1f83)

It doesn't look pretty, so if this doesn't have any impact, I'll follow this proposal.


https://github.com/llvm/llvm-project/pull/134089