shm: processes from diffierent world try to use shared memory

[hzhou]

In issue #5372, user report --

When launch the process outside docker in multiple nodes, I use mpirun to launch the process together, but when I use docker, I launch the processes Independents and then I connect them using open/connect/accept functions(All process start with a comm_world size 1 and then they create a communicator dynamically, and execute all code with it). May be MPIR_Csel_search doesn’t detect that the process in the communicator were in different nodes and return node->success enabling shared memory optimization.

Processes from different world cannot use shared memory due to missing init shm initialization. We need debug how did it happen and fix it.

[hzhou]

Redundant to #5372.