[clang] [clang] Fix sorting header paths (PR #73323)

[Ben Langmuir via cfe-commits]

benlangmuir wrote:

You could try using `clang -cc1 -E -x c-module-map` which calls `Module::print`. To trigger this code path you can follow the pattern in `darwin_specific_modulemap_hacks.m`, ie create a module like

```
$ touch Tcl/x1.h
$ touch Tcl/x2.h
$ cat Tcl/module.modulemap
module Tcl {
  module Private {
    requires excluded
    umbrella ""
  }
}

$ clang -cc1 -E -x c-module-map Tcl/module.modulemap -fmodule-name=Tcl
# 1 "Tcl/module.modulemap"
module Tcl {
  module Private {
    textual header "" { size 0 mtime 1701196669 }
    textual header "" { size 0 mtime 1701196741 }
    textual header "" { size 75 mtime 1701196655 }
  }
}
```

However I think the printing would need to be fixed to print the right header name instead of "" first.

https://github.com/llvm/llvm-project/pull/73323