Add doc tests to test script

The doc tests now contain a check that ensures that mem::swap
can't create unsound behavior, so it's critical we continue
to monitor that going forward.

Author: akern40

scripts/all-tests.sh

@@ -30,5 +30,8 @@ fi
 # Examples
 cargo nextest run --examples
 
+# Doc tests
+cargo test --doc
+
 # Benchmarks
 ([ "$CHANNEL" != "nightly" ] || cargo bench --no-run --verbose --features "$FEATURES")