[llvm] [AsmPrinter][DebugNames] Implement DW_IDX_parent entries (PR #77457)

[Greg Clayton via llvm-commits]

clayborg wrote:

> C++ doesn't allow it, but clang does generate this for C++ when using type homing/`-fno-standalone-debug`. Try this:
> 
> ```
> struct A {
>   A();
>   struct B { };
> };
> A::B b;
> ```
> 
> compiled with `-fno-standalone-debug` (or on a non-mac platform, where that's the default): https://godbolt.org/z/rYvPxPMcY

I was hoping to hear this response as I figured it must be, but wanted to make sure.

https://github.com/llvm/llvm-project/pull/77457