Rollup merge of #146000 - GuillaumeGomez:rustdoc-error-improvement, r=notriddle

Improve librustdoc error when a file creation/modification failed

The message before looks like this:

```
failed to create or modify "/build/x86_64-unknown-linux-gnu/test/rustdoc-gui/doc/search.index/entry/"
```

And with this change it looks like this:

```
failed to create or modify "/build/x86_64-unknown-linux-gnu/test/rustdoc-gui/doc/search.index/entry/": failed to read column from disk: data consumer error: missing field `unknown number` at line 1 column 8
```

r? ``````@lolbinarycat``````

Author: tgross35