[Bug c++/64859] New: -Wabi-tag is not documented

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64859

            Bug ID: 64859
           Summary: -Wabi-tag is not documented
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: doko at gcc dot gnu.org

The -Wabi-tag warning is not documented, it only shows up in gcc
--help=warnings

  -Wabi-tag                   Warn if a subobject has an abi_tag attribute that
the complete object type
                              does not have