update tests and examples

examples/full-syntax.rs

examples/generics.rs

examples/modules.rs

examples/nested.rs

examples/one-task.rs

examples/preemption.rs

examples/two-tasks.rs

tests/cfail/critical-section.rs

tests/cfail/duplicated-handler-2.rs

tests/cfail/duplicated-handler.rs

tests/cfail/local-token.rs

tests/cfail/lock.rs

tests/cfail/priority-too-high.rs

tests/cfail/priority-too-low.rs

tests/cfail/token-outlive.rs

tests/cfail/token-transfer.rs

tests/cfail/wrong-threshold.rs