[eclipse-pmc] API request: Fix breaking change to DecoratingLabelProvide

[Boris Bokowski <Boris_Bokowski@xxxxxxxxxx>]

Using the new API comparison tool from the PDE incubator, we found a
breaking API change due to changing the supertype hierarchy of
DecoratingLabelProvider.

API REQUEST

I would like to request permission to fix this. See
https://bugs.eclipse.org/bugs/show_bug.cgi?id=171612.

RISKS

Low - I checked all of Europa M5 and found no compile errors after
reverting DecoratingLabelProvider back to its 3.2.2 state.

RISKS OF NOT FIXING THIS

We would have an API change in JFace that is not binary upwards compatible.

Thanks,
Boris.