[Bug c++/87934] New: [8 regression] struct with NSDMI of enum makes initialization a non-constant expression

[m.cencora at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87934

            Bug ID: 87934
           Summary: [8 regression] struct with NSDMI of enum makes
                    initialization a non-constant expression
           Product: gcc
           Version: 8.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: m.cencora at gmail dot com
  Target Milestone: ---

Following code does not compile in g++8 and trunk, while it compiles with g++7
and older.

struct Foo
{
    enum
    {
        BAR
    } bar = BAR;
};

constexpr Foo foo{};

If bar NSDMI is changed to {}, it works. Also explicitly providing initializer
in foo variable declaration fixes it as well.