Implement guard_source on RandomValueSource (#89711)
I audited the pattern matches on the enum and it didn't
look like this one should apply there.
Sorry, no test, I know this matters on symbolic-shapes branch
but I haven't had time to extract out a minimal reproducer.
Take my word for it.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89711
Approved by: https://github.com/jansel
