Kotlin: Fix vararg extraction outside of method call

Author: tamasvajk

java/kotlin-extractor/src/main/kotlin/KotlinFileExtractor.kt

@@ -3056,7 +3056,13 @@ open class KotlinFileExtractor(
                     extractTypeOperatorCall(e, callable, exprParent.parent, exprParent.idx, exprParent.enclosingStmt)
                 }
                 is IrVararg -> {
-                    logger.errorElement("Unexpected IrVararg", e)
+                    if (e.elements.size != 1 || e.elements[0] !is IrSpreadElement) {
+                        logger.errorElement("Unexpected IrVararg", e)
+                        return
+                    }
+                    // There are lowered IR cases when the vararg expression is not within a call, such as
+                    // val temp0 = [*expr]
+                    extractExpression((e.elements[0] as IrSpreadElement).expression, callable, parent)
                 }
                 is IrGetObjectValue -> {
                     // For `object MyObject { ... }`, the .class has an

java/ql/test/kotlin/library-tests/vararg/args.expected

@@ -1,5 +1,4 @@
 diag
-| test.kt:55:15:55:35 | Unexpected IrVararg |
 varargsParams
 | test.kt:8:15:8:28 | xs | file://:0:0:0:0 | int[] |
 | test.kt:12:26:12:39 | xs | file://:0:0:0:0 | int[] |
@@ -84,3 +83,4 @@ implicitVarargsArguments
 | test.kt:45:5:45:39 | new HasVarargConstructor(...) | 1 | test.kt:45:34:45:38 | array |
 | test.kt:55:13:55:43 | new X(...) | 0 | test.kt:55:42:55:42 | 1 |
 | test.kt:55:13:55:43 | new X(...) | 1 | test.kt:55:15:55:35 | tmp0_s |
+| test.kt:55:22:55:35 | toTypedArray(...) | 0 | test.kt:55:19:55:20 | sl |