Unable to generate bindings ("Unable to get layout information?")

This seems like it might be related to #1768. I'm working to generate bindings for this file. But, I'm hitting a wall. I've proven that a simple case works, so this seems related to something potentially deep in the include-tree so I'm kind of scared to dig into this.

I've attached my build logs running my code against both of:

1. rust-bindgen 0.70.1 (upstream)
2. my fork of rust-bindgen which includes @Danielmelody's patch to try to resolve this issue. That seemed to get me farther, but it still broke.

build.upstream.txt
build.danielmelody.txt

If you have nix then you should be able to reproduce (executed on x86_64-linux) using

1. nix build -L 'github:johnrichardrinehart/f-u?rev=c3e82b4a470b0cefff91a2ac6fd22015603d020f' (upstream)
2. nix build -L 'github:johnrichardrinehart/f-u?rev=fb8f0e7aa0972c6c2ebce1ed2b4ac74779814d1d' (@Danielmelody's patch)

Start with src/lib/binding.hh and the referenced Nix flake.hh, then reproduce both cases using the two nix build commands in the issue. Compare the upstream rust-bindgen 0.70.1 logs with the fork containing the referenced patch to isolate where layout information is lost. Done means binding generation succeeds for the reported flake.hh input.