This patch adds a new matching method for data formatters, in addition
to the existing exact typename and regex-based matching. The new method
allows users to specify the name of a Python callback function that
takes a `SBType` object and decides whether the type is a match or not.
Here is an overview of the changes performed:
- Add a new `eFormatterMatchCallback` matching type, and logic to handle
it in `TypeMatcher` and `SBTypeNameSpecifier`.
- Extend `FormattersMatchCandidate` instances with a pointer to the
current `ScriptInterpreter` and the `TypeImpl` corresponding to the
candidate type, so we can run registered callbacks and pass the type
to them. All matcher search functions now receive a
`FormattersMatchCandidate` instead of a type name.
- Add some glue code to ScriptInterpreterPython and the SWIG bindings to
allow calling a formatter matching callback. Most of this code is
modeled after the equivalent code for watchpoint callback functions.
- Add an API test for the new callback-based matching feature.
For more context, please check the RFC thread where this feature was
originally discussed:
https://discourse.llvm.org/t/rfc-python-callback-for-data-formatters-type-matching/64204/11
Differential Revision: https://reviews.llvm.org/D135648