Hide atomics struct from reflection api (#7520)

* Atomic reflection unit test

Test that Atomic<int> is reflected as a scalar/int instead of a struct
named Atomic.

* Hide AtomicType from reflection

Leverage the fact that returned variables go through convert() to
centralize the unwrapping of the AtomicType struct.

Fixes #6257

* Clean up unit test a bit

- rename bar to buf (since one of them is not Atomic and thus not a
  barrier)
- validate deeper into the fields of bufC
- remove debug code

0 files changed, 0 insertions, 0 deletions