function that takes a const Foo&, where Foo is convertible from a large number
of pointer types, we print ALL the overloads, no matter the setting of
-fshow-overloads.
There is potential follow-on work in unifying the "print candidates, but not
too many" logic between OverloadCandidateSet::NoteCandidates and
ImplicitConversionSequence::DiagnoseAmbiguousConversion.
llvm-svn: 167596