[Bug c++/64629] New: [5 Regression] -Wformat-security warns with const char *const vars

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64629

            Bug ID: 64629
           Summary: [5 Regression] -Wformat-security warns with const char
                    *const vars
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
                CC: jason at gcc dot gnu.org

extern void bar (int, const char *, ...) __attribute__((format (printf, 2,
3)));
void
foo (void)
{
  const char *const msg = "abc";
  bar (1, msg);
}

started warning with -Wformat -Wformat-security with r217814.  Was that an
intentional change for this case?
Seen on libcpp/, where the first hunk no longer works around the warning
while it used to work with gcc 4.9 and earlier.