fix code completion test

Author: kavon

test/SourceKit/CodeComplete/complete_override.swift.response

@@ -1,5 +1,15 @@
 {
   key.results: [
+    {
+      key.kind: source.lang.swift.keyword,
+      key.name: "_compilerInitialized",
+      key.sourcetext: "_compilerInitialized",
+      key.description: "_compilerInitialized",
+      key.typename: "",
+      key.context: source.codecompletion.context.none,
+      key.typerelation: source.codecompletion.typerelation.notapplicable,
+      key.num_bytes_to_erase: 0
+    },
     {
       key.kind: source.lang.swift.keyword,
       key.name: "_const",