[llvm] Add release notes for LLDB inline diagnostics (PR #116841)

[David Spickett via llvm-commits]

DavidSpickett wrote:

I know I'm the one who asked you to release note this, but somehow I forgot about it and got this today:
```
(lldb) expression *(char[4])b
                   ˄˜˜˜˜˜˜˜˜
                   ╰─ error: C-style cast from 'int *' to 'char[4]' is not allowed
```
I was quite shocked to see the sort of diagnostics I expect from rustc, but in lldb. This is a great feature @adrian-prantl !

Definitely falls into the category of things users didn't know needed to be improved, but it's clearly an improvement once it's done.

https://github.com/llvm/llvm-project/pull/116841