Currently, `ParserVerifier#verifyConstantPool` uses a `switch` to produce a `Runnable`, which is consumed by a `Consumer<Runnable>` (instantiated within a loop) which runs the task inside if a `try`/`catch`. We can eliminate a number of lambdas and method references, plus some allocation pressure, in this code by simplifying it so that the `switch` is itself run directly within the `try`/`catch`.