Auto merge of #114350 - erikdesjardins:ident, r=tmiasko

cg_llvm: stop identifying ADTs in LLVM IR

This is an extension of rust-lang/rust#94107. It may be a minor perf win.

Fixes #96242.

Now that we use opaque pointers, ADTs can no longer be recursive, so we
do not need to name them. Previously, this would be necessary if you had
a struct like

```rs
struct Foo(Box<Foo>, u64, u64);
```

which would be represented with something like

```ll
%Foo = type { %Foo*, i64, i64 }
```

which is now just

```ll
{ ptr, i64, i64 }
```

r? `@tmiasko`