[Bug c++/71147] New: [6 REGRESSION] Flexible array member wrongly rejected in template

[avi@cloudius-systems.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71147

            Bug ID: 71147
           Summary: [6 REGRESSION] Flexible array member wrongly rejected
                    in template
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: avi@cloudius-systems.com
  Target Milestone: ---

Created attachment 38497
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38497&action=edit
Reproducer

gcc (GCC) 6.1.1 20160510 (Red Hat 6.1.1-2)

The attached code does not compile under g++ 6.  It works fine under 5.3 (with
-std=gnu++14).

Removing "template <typename T>, or converting the array to be an array of
unsigned (instead of array of struct) hides the problem.