Re: [PATCH] Extend the length of BackgroundWorker.bgw_library_name

> The patch is backwards-compatible and ensures that bgw_library_name stays *at least* as long as BGW_MAXLEN. Existing external code that uses BGW_MAXLEN is a length boundary (for example, in `strncpy`) will continue to work as expected.

There is a mistake in the comment though:

```
+/*
+ * Ensure bgw_function_name's size is backwards-compatible and sensible
+ */
+StaticAssertDecl(MAXPGPATH >= BGW_MAXLEN, "MAXPGPATH must be at least
equal to BGW_MAXLEN");
```

library_name, not function_name. Also I think the comment should be
more detailed, something like "prior to PG17 we used ... but since
PG17 ... which may cause problems if ...".