Add tests for BindableRuntimeHintsRegistrar

[philwebb]

Whilst refactoring ConfigurationPropertiesReflectionHintsProcessor to BindableRuntimeHintsRegistrar I realized we don't seem to have any tests it.

[tumit]

Can i try to take care this issue ?

[philwebb]

That would be great. Thanks @tumit

[mhalbritter]

It's implicitly tested in ConfigurationPropertiesBeanFactoryInitializationAotProcessorTests.

[philwebb]

Thanks @mhalbritter. I figured we must have tested it somewhere but I couldn't find it.

[mhalbritter]

Should we move the tests to BindableRuntimeHintsRegistrarTests or is it fine the way it is?

[philwebb]

I did add a comment to ConfigurationPropertiesBeanFactoryInitializationAotProcessorTests saying it also tests BindableRuntimeHintsRegistrar. It was meant to be a polish commit but I accidentally did it in e6c37d6 🤭.

I wouldn't mind having the BindableRuntimeHintsRegistrar logic tested in a BindableRuntimeHintsRegistrarTests just because it's a bit closer to the code and a bit more discoverable. It certainly not a pressing matter.

[philwebb]

I've copied a lot of the tests from ConfigurationPropertiesBeanFactoryInitializationAotProcessorTests over when merging #32851. There's some duplication now, but the tests are quick so I think it's fine.