[Chapel Merge] Add tests to track what happens when an operator o

Branch: refs/heads/master
Revision: 4dd295c
Author: lydia-duncan
Log Message:

Merge pull request #16372 from lydia-duncan/visibilityAndTypeTests

Add tests to track what happens when an operator on a type is private
[tests discussed with Michael, not reviewed]

Checks that the operator is used in the scope in which it is defined, and can’t
be found outside of it.

Passed a fresh checkout

Modified Files:
A test/visibility/private/functions/privateOperator.chpl
A test/visibility/private/functions/privateOperator.good
A test/visibility/private/functions/privateOperatorError.chpl
A test/visibility/private/functions/privateOperatorError.good
A test/visibility/private/functions/privateOperatorError2.chpl
A test/visibility/private/functions/privateOperatorError2.good

Compare: https://github.com/chapel-lang/chapel/compare/8429ecc72fb6...4dd295cd9a78