Fix PDB reading.
Seen with PDB generated with "latest" MS compiler.
The data here is likely to be in the same form of other hash structures we already handle. (eg has a first vector to describe present entries, and a second one to describe deleteid entries; we were incorrectly expecting an empty deleted vector... so just skip for now the deleted vector in winedump and dbghelp... this will probably end up with a more generic code for reloading such hash structures, but after code freeze).