Let's say we've run llvm-strip over some MachO. The resulting MachO
became smaller and there are no indirect symbols anymore.
Then according to previous code we would not update indirectsymoff
field. This would lead to `MachOWriter::totalSize()` report size that is
larger than the new MachO. As a result we would get MachO that has zero
bytes past contents of the very last load command.
Codesign has a strict check that size of MachO file must be equal to
lastLoadCommand.offset + lastLoadCommand.size
If this is not satisfied codesign reports the following error
main executable failed strict validation
Fixes#117723
9c97aa5abb