This pull request allows me to build and run all dbus unit tests successfully on my Arm Morello board (https://www.arm.com/architecture/cpu/morello).
Arm Morello is a CHERI-enabled architecture that uses 128-bit pointers with bounds and permissions. As some of the code here assumes 4 or 8 byte pointers I had to make a few minor changes to support a pointer size and alignment of 16 bytes.
This pull request can be tested also be tested in QEMU using the cheribuild tool (https://github.com/CTSRD-CHERI/cheribuild) by running these commands (will take a long time since it involves building LLVM):
$ cheribuild.py dbus-morello-purecap disk-image-minimal-morello-purecap --include-dependencies
$ cheribuild.py dbus-morello-purecap --testNB: when running the test in QEMU instead of on real hardware, merge request !334 (merged) is also needed since sockets cannot be created on smbfs.