Extract Function: Support multiple output values

idea/testData/refactoring/extractFunction/controlFlow/outputValues/pairWithWhen.kt

@@ -0,0 +1,25 @@
+// WITH_RUNTIME
+// PARAM_TYPES: kotlin.Int
+// PARAM_TYPES: kotlin.Int
+// PARAM_TYPES: kotlin.Int
+// PARAM_DESCRIPTOR: value-parameter val a: kotlin.Int defined in foo
+// PARAM_DESCRIPTOR: var b: kotlin.Int defined in foo
+// PARAM_DESCRIPTOR: var c: kotlin.Int defined in foo
+// SIBLING:
+fun foo(a: Int): Int {
+    var b: Int = 1
+    var c: Int = 1
+
+    <selection>when {
+        a > 0 -> {
+            b += a
+        }
+        else -> {
+            c -= a
+        }
+    }
+    println(b)
+    println(c)</selection>
+
+    return b + c
+}