Smart completion after "by" and "in": non-imported operators supported

idea/idea-completion/testData/smartMultiFile/NotImportedContains/Declarations.kt

@@ -0,0 +1,8 @@
+package dependency
+
+interface X
+interface Y : X
+interface Z
+
+operator fun X.contains(s: String): Boolean = true
+fun Z.contains(s: String): Boolean = true

idea/idea-completion/testData/smartMultiFile/NotImportedContains/NotImportedContains.kt

@@ -0,0 +1,11 @@
+import dependency.X
+import dependency.Y
+import dependency.Z
+
+fun foo(s: String, x: X, y: Y, z: Z) {
+    if (s in <caret>)
+}
+
+// EXIST: x
+// EXIST: y
+// ABSENT: z