A class or a struct type A can be a forward declaration and refer
to another type B in PDB, so we need to follow the references.
We pre-create type for B, when we face type A, and then, when we
visit type B, we populate the fields for the model::type we
pre-created.
In addition, this patch fixes some minor/side bugs:
- Handle SHORT/Int16Short simple type
- Do not delete model::Function if Prototype is invalid.
This commit switches from `deduplicateNames`, which changed certain
`CustomName` values, to `promoteOriginalName`, which updates empty
`CustomName` using non-ambiguous versions of `OriginalName`.
Model classes are now described by a YAML document, which is used to
generate C++ headers containing classes and all the boilerplate
required for YAML serialization/deserialization, usage in
SortedVectors, etc. See the README in include/revng/Model for more
info.
Ivan Krysak