Add .equalsExpected.(logical, logical)

[bonachea]

I just happened to notice that Julienne lacks an overload for .equalsExpected.(logical, logical), i.e. the test_diagnosis_t equivalent of the F23 .EQV. operator. This might occasionally be useful when comparing two logical values where neither is statically known.

Of course you can do something like .expect.(l1 .eqv. l2), but that loses the diagnostic information about dynamic variable values on failure.