Add wildcard parameter case to VariableType test

Author: fwcd

test/SourceKit/VariableType/params.swift

@@ -8,9 +8,13 @@ let z = { (param: String) in
   param.count
 }
 
+let w: (String, Int) -> Void = { (_, x) in }
+
 // RUN: %sourcekitd-test -req=collect-var-type %s -- %s | %FileCheck %s
 // CHECK: (1:10, 1:15): Int (explicit type: 1)
 // CHECK: (5:5, 5:6): (String) -> Void (explicit type: 1)
 // CHECK: (5:29, 5:34): String (explicit type: 0)
 // CHECK: (7:5, 7:6): (String) -> Int (explicit type: 0)
 // CHECK: (7:12, 7:17): String (explicit type: 1)
+// CHECK: (11:35, 11:36): String (explicit type: 0)
+// CHECK: (11:38, 11:39): Int (explicit type: 0)