[binutils-gdb] sim: standardize sim_create_inferior handling of argv a bit more

[sergiodj+buildbot at redhat dot com]

*** TEST RESULTS FOR COMMIT 0e9672991e9346d5c2cb9cd33e30fb3e573f88b8 ***

Author: Mike Frysinger <vapier@gentoo.org>
Branch: master
Commit: 0e9672991e9346d5c2cb9cd33e30fb3e573f88b8

sim: standardize sim_create_inferior handling of argv a bit more

For targets that process argv in sim_create_inferior, improve the code:
- provide more details in the comment
- make the check for when to re-init more robust
- clean out legacy sim_copy_argv code

This will be cleaned up more in the future when we have a common inferior
creation function, but at least help new ports get it right until then.