Merge #17018: tests: Add descriptor Parse(...) fuzzing harness
b5ffa9f3dbff7dd008d4d00a88590d411ef991f2 tests: Add Parse(...) (descriptor) fuzzing harness (practicalswift) fdef8bbf2f824a87f70b755155e9e1a8cd19fdcb tests: Allow for using non-default fuzzing initialization (practicalswift) Pull request description: Add `Parse(...)` (descriptor) fuzzing harness.
Depends on D6880
Backport of Core PR17018