[Bug c++/67105] New: use of global register variables should emit a pedwarn

[daniel.gutson at tallertechnologies dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67105

            Bug ID: 67105
           Summary: use of global register variables should emit a pedwarn
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: daniel.gutson at tallertechnologies dot com
  Target Milestone: ---

This is a spinoff of https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67064
specially comment https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67064#c16

So basically:

struct s {
  int i;
};
register struct s *reg asm( "si" );

should pedwarn.