[Bug c++/93933] New: [concepts] redeclaration of constrained template give error

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93933

            Bug ID: 93933
           Summary: [concepts] redeclaration of constrained template give
                    error
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: nathan at gcc dot gnu.org
  Target Milestone: ---

Created attachment 47912
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47912&action=edit
testcase

I fell over this on the modules branch, but discovered it also occurring on
trunk.  We consider all TYPE_ARGUMENT_PACKS different.

I have a patch.