[Bug c++/94050] New: [10 Regression] C++ ABI change on armv7hl-linux-gnueabi since r10-1302

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94050

            Bug ID: 94050
           Summary: [10 Regression] C++ ABI change on
                    armv7hl-linux-gnueabi since r10-1302
           Product: gcc
           Version: 9.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
  Target Milestone: ---

Since r10-1302-gc3337b44c40dd1545e00034cb8e1ae1c0dae0fa6
the following test FAILs on armv7hl-linux-gnueabi (but not on i686 or x86_64).
This breaks at least mozjs68 build:

struct alignas(8) Cell {};
struct TenuredCell : public Cell {};
struct BaseShape : public TenuredCell {
  void *p;
  unsigned q, r;
  void *s;
  __UINTPTR_TYPE__ t;
};
static_assert (sizeof (BaseShape) % 8 == 0, "");