Rollup merge of rust-lang#53703 - sourcefrog:doc-wrapping, r=frewsxcv

Document .0 to unpack integer from Wrapping

Author: kennytm

src/libcore/num/mod.rs

@@ -122,6 +122,9 @@ nonzero_integers! {
 /// all standard arithmetic operations on the underlying value are
 /// intended to have wrapping semantics.
 ///
+/// The underlying value can be retrieved through the `.0` index of the
+/// `Wrapping` tuple.
+///
 /// # Examples
 ///
 /// ```