[clang] [clang-tools-extra] [clang] Improve nested name specifier AST representation (PR #147835)

[Matheus Izvekov via cfe-commits]

mizvekov wrote:

> Hi, I'm helping fix some clang-as-a-library users and I'm running into some issues with the TypePrinter after this commit. Specifically the clang generator in sandboxed-api is broken (https://github.com/google/sandboxed-api/tree/main). After doing the trivial fixes (`getDecl` -> `getOriginalDecl`) some of the tests are failing (https://github.com/google/sandboxed-api/blob/main/sandboxed_api/tools/clang_generator/emitter_test.cc).

The NestedAnonymousStruct case seems to be missing a `IncludeTagDefinition` PrintingPolicy set to true.


https://github.com/llvm/llvm-project/pull/147835