Control-Flow: Fix pseudocode generation for combined get/set and invoke conventions

#KT-4462 Fixed
 #KT-4681 Fixed

compiler/testData/cfg/conventions/setViaVar.kt

@@ -0,0 +1,15 @@
+class Bar {
+    fun invoke(x: Int, y: Int) {}
+}
+
+class Foo {
+    val set: Bar = Bar()
+}
+
+fun test1(foo: Foo) {
+    foo[1] = 2
+}
+
+fun test2(foo: Foo, set: Foo.(Int, Int) -> Int) {
+    foo[1] = 2
+}