[Bug c++/69753] New: [6 Regression] bogus: expected primary-expression before ‘>’ token

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69753

            Bug ID: 69753
           Summary: [6 Regression] bogus: expected primary-expression
                    before ‘>’ token
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
  Target Milestone: ---

A very recent regression. Yesterdays gcc was fine.
Chromium fails to build due to the following bogus error:

markus@x4 Release % g++ -c -march=native generated_api_registration.ii
In file included from
../../extensions/browser/guest_view/web_view/web_view_guest.h:14:0,
                 from
../../extensions/browser/api/guest_view/web_view/web_view_internal_api.h:15,
                 from
gen/extensions/browser/api/generated_api_registration.cc:9:
../../components/guest_view/browser/guest_view.h: In static member function
‘static T* guest_view::GuestView<T>::From(int, int)’:
../../components/guest_view/browser/guest_view.h:25:23: error: expected
primary-expression before ‘>’ token
     return guest->As<T>();
                       ^
../../components/guest_view/browser/guest_view.h:25:25: error: expected
primary-expression before ‘)’ token
     return guest->As<T>();
                         ^
../../components/guest_view/browser/guest_view.h: In static member function
‘static T* guest_view::GuestView<T>::FromWebContents(const
content::WebContents*)’:
../../components/guest_view/browser/guest_view.h:30:31: error: expected
primary-expression before ‘>’ token
     return guest ? guest->As<T>() : nullptr;
                               ^
../../components/guest_view/browser/guest_view.h:30:33: error: expected
primary-expression before ‘)’ token
     return guest ? guest->As<T>() : nullptr;


Reducing...