OpenSystemsDevelopment / qpdf

Also add new fuzz test case.

QPDF::processXRefStream

A file that has Widget annotations that can't be mapped back to form
fields would crash qpdf json.

Change the processed Index array to a vector of <first object, number of
entries> pairs.

Add closure damaged to create damagedPDF exceptions.

Tune processing of subsections.

Tune pointer arithmetic.

Apply temporary fix to deal with fuzz case 68915.

(Error is an integer overflow which would immediately cause a runtime error
as a result of a call to QInitCQIntC::to_size.)

Code failed to allow for QPDF::getCompressibleObjSet deleting objects
from the object cache in case of multiple entries for the same object id.

Add fuzz test case 68668.

Add fuzz case 68377.

Tune QPDFWriter

Create set without creation of an intermediate vector.

This triggers compilation failures with certain C++20 compiler configurations.

To avoid this I moved the cast to the loop's body.