[Bug ipa/83549] New: [7/8 Regression] error: generic thunk code fails for method ... which uses '...'

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83549

            Bug ID: 83549
           Summary: [7/8 Regression] error: generic thunk code fails for
                    method ... which uses '...'
           Product: gcc
           Version: 7.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
                CC: marxin at gcc dot gnu.org
  Target Milestone: ---

struct A { virtual ~A (); };
struct B { virtual void foo (...); };
struct C : A, B { void foo (...) {} };
C c;

compiles fine at -O0, but starting with most probably r236274 it fails at -O1+
with:
rh1511021.C:4:4: error: generic thunk code fails for method ‘virtual void
C::_ZThn8_N1C3fooEz(...)’ which uses ‘...’

Perhaps we should revert the change for thunks with ..., i.e. make them
uninlinable again?