Smart completion after ?: works incorrectly

#KT-4926 Fixed

idea/testData/completion/handlers/smart/InElvisOperator.kt

@@ -0,0 +1,7 @@
+fun foo(s: String, c: Char){}
+
+fun bar(p1: String?, p2: String) {
+    foo(p1 ?: <caret>
+}
+
+// ELEMENT: p2

idea/testData/completion/handlers/smart/InElvisOperator.kt.after

@@ -0,0 +1,7 @@
+fun foo(s: String, c: Char){}
+
+fun bar(p1: String?, p2: String) {
+    foo(p1 ?: p2, <caret>
+}
+
+// ELEMENT: p2

idea/testData/completion/smart/InElvisOperator1.kt

@@ -0,0 +1,9 @@
+fun foo(p: String?){}
+fun foo(p: Char){}
+
+fun bar(p1: String?, p2: String?, p3: Char) {
+    foo(p1 ?: <caret>
+}
+
+// EXIST: { itemText:"p2" }
+// ABSENT: p3

idea/testData/completion/smart/InElvisOperator2.kt

@@ -0,0 +1,12 @@
+fun foo1(): String? = null
+fun foo2(): String? = null
+fun foo3(): String = ""
+
+fun bar() {
+    foo1() ?: <caret>
+}
+
+// EXIST: { itemText:"foo3()" }
+// ABSENT: { itemText:"foo2()" }
+// EXIST: { itemText:"!! foo2()" }
+// EXIST: { itemText:"?: foo2()" }