When a registered class has a non-registered superclass,
rna_info.BuildRNAInfo entered an eternal loop.
The while loop in `rna_info.get_py_class_from_rna` was not mutating the
variables within the loop nor the variable in its condition, meaning it
would loop infinitely if the loop didn't exit in its first iteration.
When yielding registered classes in `subclasses_recurse`, the function
was erroneously checking if the class' superclass was registered rather
than checking the class itself, causing registered classes to be skipped
if their superclass was not also registered. If the class to be found
was skipped, the while loop would not exit in its first iteration and
would thus loop infinitely.
The while loop has been modified to iterate through each base rna type
until there is no further base type.
The `subclasses_recurse` function now correctly checks whether the
subclass is registered, not its superclass, when determining if the
subclass should be yielded.
Besides the fix, no functional changes are expected, the generated
Python API docs remain unchanged.
Ref: !108256
Thomas Barlow
d1cff7974a