When custom include filters are specified on the command line, it is possible for jextract to generate non-sensical code (now even more so than in the past). Possible issues:

* a function descriptor refers to a non-existent struct/union
* a struct/union typedef refers to a non-existent struct/union
* a struct/union field refers to a non-existent struct/union
* a global variable refers to a non-existent struct/union

In such cases, jextract should terminate (and report the problem to the user), rather than generating buggy code.