applyNonNullConstraint method
Applies a null check constraint.
If we know x != null, then x becomes definitelyNonNull.
Implementation
NullabilityDomain applyNonNullConstraint() {
if (isBottom) return bottomValue;
if (state == Nullability.definitelyNull) {
return bottomValue; // Contradiction: null != null is false
}
return nonNullValue;
}