[Bug c++/71773] [7 Regression] bogus? error: invalid use of incomplete type

["trippels at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71773

Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2016-08-05
     Ever confirmed|0                           |1

--- Comment #2 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
This happens a lot when trying to build Chromium:

In file included from ../../v8/src/heap/spaces.h:20:0,
                 from ../../v8/src/heap/heap.h:20,
                 from ../../v8/src/contexts.h:8,
                 from ../../v8/src/api.h:9,
                 from ../../v8/src/ast/ast-value-factory.h:31,
                 from ../../v8/src/ast/variables.h:8,
                 from ../../v8/src/ast/scopeinfo.h:10,
                 from ../../v8/src/ast/scopeinfo.cc:5:
../../v8/src/objects.h: In member function ‘uint32_t
v8::internal::HashTable<Derived, Shape, Key>::Hash(Key)’:
../../v8/src/objects.h:3244:46: error: invalid use of incomplete type ‘class
v8::internal::Heap’
       return Shape::SeededHash(key, GetHeap()->HashSeed());
                                              ^~
In file included from ../../v8/src/allocation.h:8:0,
                 from ../../v8/src/ast/scopeinfo.h:8,
                 from ../../v8/src/ast/scopeinfo.cc:5:
../../v8/src/globals.h:412:7: note: forward declaration of ‘class
v8::internal::Heap’
 class Heap;
       ^~~~
In file included from ../../v8/src/heap/spaces.h:20:0,
                 from ../../v8/src/heap/heap.h:20,
                 from ../../v8/src/contexts.h:8,
                 from ../../v8/src/api.h:9,
                 from ../../v8/src/ast/ast-value-factory.h:31,
                 from ../../v8/src/ast/variables.h:8,
                 from ../../v8/src/ast/scopeinfo.h:10,
                 from ../../v8/src/ast/scopeinfo.cc:5:
../../v8/src/objects.h: In member function ‘uint32_t
v8::internal::HashTable<Derived, Shape, Key>::HashForObject(Key,
v8::internal::Object*)’:
../../v8/src/objects.h:3252:55: error: invalid use of incomplete type ‘class
v8::internal::Heap’
       return Shape::SeededHashForObject(key, GetHeap()->HashSeed(), object);
                                                       ^~
In file included from ../../v8/src/allocation.h:8:0,
                 from ../../v8/src/ast/scopeinfo.h:8,
                 from ../../v8/src/ast/scopeinfo.cc:5:
../../v8/src/globals.h:412:7: note: forward declaration of ‘class
v8::internal::Heap’
 class Heap;
       ^~~~