misc/examples.lean currently PANICs

[kim-em]

Either diagnose and fix, or at very least comment out.

[bryangingechen]

This was commented out in https://github.com/leanprover-community/quote4/pull/108/files#diff-d145b90fb729a769adec1dfe0043f229fac2a54f6573370f7b5fa58ecc5ab4ae.

Not sure if it's related but I noticed another one of the tests in the file leads to a panic if turned into an example, so I made a note of it there too.