[BOLT][NFC] Don't assign YAML profile to functions with no CFG (#92487)

YAML profile for non-simple functions without CFG is
  1) useless for optimizations,
  2) can't be attached, similar to fdata profile,
  3) would be reported as invalid/stale even if the profile is valid.

Don't attempt to attach the profile in this case, aligning the behavior
to DataReader.

Test Plan: added yaml-non-simple.test