feat(spdx-utils): Deduplicate equal SpdxCompoundExpression operands

Calculating whether expressions are equal might be a bit computation
intensive for huge expressions, but the idea with this change is that
expression should not grow huge to begin with.

Signed-off-by: Sebastian Schuberth <[email protected]>

utils/spdx/src/main/kotlin/SpdxExpression.kt

@@ -201,13 +201,13 @@ sealed class SpdxExpression {
      * Concatenate [this][SpdxExpression] and [other] using [SpdxOperator.AND].
      */
     infix fun and(other: SpdxExpression) =
-        takeIf { this == other } ?: SpdxCompoundExpression(SpdxOperator.AND, listOf(this, other))
+        takeIf { this == other } ?: SpdxCompoundExpression(SpdxOperator.AND, setOf(this, other))
 
     /**
      * Concatenate [this][SpdxExpression] and [other] using [SpdxOperator.OR].
      */
     infix fun or(other: SpdxExpression) =
-        takeIf { this == other } ?: SpdxCompoundExpression(SpdxOperator.OR, listOf(this, other))
+        takeIf { this == other } ?: SpdxCompoundExpression(SpdxOperator.OR, setOf(this, other))
 }
 
 /**
@@ -224,14 +224,14 @@ class SpdxCompoundExpression(
      * Create a compound expression with the provided [operator] and the [left] and [right] child expressions.
      */
     constructor(left: SpdxExpression, operator: SpdxOperator, right: SpdxExpression) :
-        this(operator, listOf(left, right))
+        this(operator, setOf(left, right))
 
     /**
      * Create a compound expression with the provided [operator], the [first] and [second] child expressions, and an
      * arbitrary number of [other] child expressions.
      */
     constructor(operator: SpdxOperator, first: SpdxExpression, second: SpdxExpression, vararg other: SpdxExpression) :
-        this(operator, listOf(first, second, *other))
+        this(operator, setOf(first, second, *other))
 
     init {
         require(children.size > 1) {