[Bug libgomp/97331] New: [nvptx] Provide GCN_NUM_TEAMS/GCN_NUM_THREADS equivalent

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97331

            Bug ID: 97331
           Summary: [nvptx] Provide GCN_NUM_TEAMS/GCN_NUM_THREADS
                    equivalent
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: libgomp
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vries at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org
  Target Milestone: ---

When looking at the gcn plugin, there are a number of environment variables
that set/limit launch dimensions:
...
$ grep getenv libgomp/plugin/plugin-gcn.c | grep NUM
  const char *x = secure_getenv ("GCN_NUM_TEAMS");
    x = secure_getenv ("GCN_NUM_GANGS");
  const char *z = secure_getenv ("GCN_NUM_THREADS");
    z = secure_getenv ("GCN_NUM_WORKERS");
...

It would be nice to have similar ones for nvptx.