KT-4908 Smart completion does not work for arguments of function with vararg

#KT-4908 Fixed

idea/idea-completion/testData/smart/Vararg1.kt

@@ -0,0 +1,8 @@
+fun foo(vararg strings: String){ }
+
+fun bar(s: String, arr: Array<String>){
+    foo(<caret>)
+}
+
+// EXIST: s
+// EXIST: { lookupString: "arr", itemText: "*arr" }

idea/idea-completion/testData/smart/Vararg2.kt

@@ -0,0 +1,9 @@
+fun foo(vararg strings: String){ }
+
+fun bar(s: String, arr: Array<String>){
+    foo("", <caret>)
+}
+
+// EXIST: s
+// ABSENT: arr
+// ABSENT: *arr

idea/idea-completion/testData/smart/Vararg3.kt

@@ -0,0 +1,7 @@
+fun foo(vararg strings: String, options: Int = 0){ }
+
+fun bar(s: String){
+    foo("", <caret>)
+}
+
+// EXIST: s

idea/idea-completion/testData/smart/Vararg4.kt

@@ -0,0 +1,9 @@
+fun foo(vararg args: Any){ }
+
+fun bar(s: String, arr: Array<String>){
+    foo(<caret>)
+}
+
+// EXIST: s
+// EXIST: { lookupString: "arr", itemText: "arr" }
+// EXIST: { lookupString: "arr", itemText: "*arr" }