[clang-tools-extra] [clangd] Show alignment for records and fields decls (PR #67213)

[Vlad Serebrennikov via cfe-commits]

Endilll wrote:

On the topic of ABI, Itanium and Microsoft type layouts are not compatible, even for standard-layout (POD) types. For [example](https://godbolt.org/z/zxfvMa9nE), bit-fields are [allowed](http://eel.is/c++draft/class.prop#3) in standard-layout types, but only Microsoft ABI mandates that bit-fields of different types can't be combined, and have to be padded. That's why almost all bit-fields in Clang are `unsigned`, without regards to types of values they hold. So author did the right thing asking Clang for alignment of types. 

Triviality is another aspect of what has been known as POD, and has nothing to do with layouts: http://eel.is/c++draft/class.prop#2

https://github.com/llvm/llvm-project/pull/67213