Keith Cooper has released several hours of video lectures online that explicitly follow the 3rd Edition’s chapter structure. These, combined with the free online course materials from Rice University, might eliminate your need for the PDF entirely.
The 3rd edition of "Engineering a Compiler" has been significantly updated to reflect the latest advancements in compiler design and implementation. Some of the key changes include: engineering a compiler 3rd edition pdf github
While I can't directly provide you with a PDF, I can guide you on how to find it. Keith Cooper has released several hours of video