Added tests

#KT-6179 Fixed
  #KT-8132 Fixed

idea/idea-completion/testData/handlers/smart/kt6179filterTo.kt

@@ -0,0 +1,10 @@
+import java.util.ArrayList
+
+fun foo(c: Collection<String>) {
+    val list = ArrayList<String>()
+    c.filterTo0(<caret>)
+}
+
+fun <T, C : MutableCollection<in T>> Iterable<T>.filterTo0(destination: C, predicate: (T) -> Boolean): C = destination
+
+//ELEMENT: list

idea/idea-completion/testData/handlers/smart/kt6179filterTo.kt.after

@@ -0,0 +1,10 @@
+import java.util.ArrayList
+
+fun foo(c: Collection<String>) {
+    val list = ArrayList<String>()
+    c.filterTo0(list)
+}
+
+fun <T, C : MutableCollection<in T>> Iterable<T>.filterTo0(destination: C, predicate: (T) -> Boolean): C = destination
+
+//ELEMENT: list