For API annotations I am working in the details of RdrNames, which come in a bewildering variety of syntactic forms.

My latest change causes perf/compiler to fail, with

bytes allocated value is too high:
    Expected    parsing001(normal) bytes allocated: 587079016 +/-5%
    Lower bound parsing001(normal) bytes allocated: 557725065
    Upper bound parsing001(normal) bytes allocated: 616432967
    Actual      parsing001(normal) bytes allocated: 704940512
    Deviation   parsing001(normal) bytes allocated:      20.1 %

I am now adding an `AnnVal` to every RdrName, to be able to separate it out from any decoration, such as surrounding backticks or parens.

Is this a problem? The alternative would be to add a SourceText field to RdrName.

Alan