This is serie #11 about PDB rewrite.
It finishes the migration of the types management to the new PDB reader (also disabling remaining type handling in old PDB reader when using new PDB reader). It starts the handling in new PDB reader of functions and symbols: - it implements line information support in new PDB reader for inlined functions, - it uses (for all debug info backend) the opaque symref_t to refer to symbol's container (so that we can let backend decide how to store it).