KT-4976 Completion ignores smart casts

#KT-4976 Fixed
 #KT-5718 Fixed

idea/testData/quickfix/autoImports/withAutoCastedQualifier.after.kt

@@ -0,0 +1,14 @@
+// "Import" "true"
+// ERROR: Unresolved reference: foo
+
+package c
+
+import g.foo
+
+class B
+
+fun test(a: Any) {
+    if (a is B) {
+        a.<caret>foo()
+    }
+}

idea/testData/quickfix/autoImports/withAutoCastedQualifier.before.Main.kt

@@ -0,0 +1,12 @@
+// "Import" "true"
+// ERROR: Unresolved reference: foo
+
+package c
+
+class B
+
+fun test(a: Any) {
+    if (a is B) {
+        a.<caret>foo()
+    }
+}

idea/testData/quickfix/autoImports/withAutoCastedQualifier.before.data.Sample.kt

@@ -0,0 +1,5 @@
+package g
+
+import c.B
+
+fun B.foo() {}