Docs for `CStr.as_ptr()` are describing `CString`

[gribozavr]

The documentation for CStr.as_ptr() is identical to docs for CString.as_ptr() and does not work for CStr. For instance, the provided code samples don't even create a CStr.

[jyn514]

@gribozavr are you interested in making a PR to fix it? :)

[eggyal]

Sorry, I should have done this earlier!
@rustbot claim

[dtolnay]

@rustbot release-assignment

[hkBst]

@rustbot claim

[workingjubilee]

calling CString::new("whatever").as_ptr() does in fact call as_ptr() on CStr, because it autoderefs from CString to CStr, and it's the most common case of the problem. revising this was rejected in #84000 and no one has come up with a better example in the meantime. we will not fix this issue because it does not actually describe a problem that exists.