Support trailing comma

^KT-34743 Fixed

compiler/testData/codegen/box/trailingComma/noDisambiguation.kt

@@ -0,0 +1,10 @@
+// !LANGUAGE: +TrailingCommas
+
+fun foo(vararg x: Int) = false
+fun foo(x: Int) = true
+
+fun box(): String {
+    val x = foo(1)
+    val y = foo(1,)
+    return if (x && y) "OK" else "ERROR"
+}