complete type inference(*) for variable as function call as well

* dependent on expected type
+ get rid of instanceof ResolvedCallImpl check

compiler/testData/diagnostics/tests/inference/nestedCalls/completeNestedCallsInference.kt

@@ -0,0 +1,19 @@
+package a
+
+import java.util.ArrayList
+
+public fun <T> Iterable<T>.withIndices(): List<Pair<Int, T>> {
+    val answer = ArrayList<Pair<Int, T>>()
+    var nextIndex = 1
+    for (e in this) {
+        answer.add(Pair(nextIndex, e))
+        nextIndex++
+    }
+    return answer
+}
+
+//from standard library
+public class Pair<out A, out B>(
+    public val first: A,
+    public val second: B
+)