Remove guardEnsuresEqUnordered and update tests

GuardCondition::ensuresEq is sufficient.
Update test-cases and expected results + removed a QL warning

solutions/Exercise4.ql

@@ -24,17 +24,6 @@ class TypeValidationCall extends FunctionCall {
   TypeValidationCall() { this.getTarget().hasName("DYN_INPUT_TYPE") }
 }
 
-/**
- * Holds if `op1` and `op2` are checked for equality in any order
- * with no distinction between left and right operands of the equality check
- */
-predicate guardEnsuresEqUnordered(
-  Expr op1, Expr op2, GuardCondition guard, BasicBlock block, boolean areEqual
-) {
-  guard.ensuresEq(op1, op2, 0, block, areEqual) or
-  guard.ensuresEq(op2, op1, 0, block, areEqual)
-}
-
 /**
  * Relates a `call` to a `guard`, which uses the result of the call to validate
  * equality of the result of `call` against `other` to guard `block`.
@@ -44,7 +33,7 @@ predicate typeValidationGuard(
 ) {
   exists(Expr dest |
     DataFlow::localExprFlow(call, dest) and
-    guardEnsuresEqUnordered(dest, other, guard, block, true) and
+    guard.ensuresEq(dest, other, 0, block, true) and
     InputTypesToTypeValidation::hasFlowToExpr(other)
   )
 }