Accept performance shifts from ghc-internal restructure

As expected, Haddock now does more work. Less expected is that some
other testcases actually get faster, presumably due to less interface
file loading. As well, the size_hello_artifact test regressed a bit when
debug information is enabled due to debug information for the new stub
symbols.

Metric Decrease:
    T12227
    T13056
Metric Increase:
    haddock.Cabal
    haddock.base
    MultiLayerModulesTH_OneShot
    size_hello_artifact