do not insert spaces in function definition after void or type with no argument name

BUG:302587

Hint: basically done by Milian to trick me into being able to fix some of my
problems myself later.

languages/cpp/codecompletion/helpers.cpp

@@ -166,7 +166,10 @@ void createArgumentList(const NormalDeclarationCompletionItem& item, QString& re
           ret += Cpp::shortenedTypeString(type, ctx, 1000000);
         }else
           ret += Cpp::shortenedTypeString(type, ctx, desiredArgumentTypeLength, item.stripPrefix());
-        ret += " " + (*paramNameIt)->identifier().toString();
+        const QString ident = (*paramNameIt)->identifier().toString();
+        if (!ident.isEmpty()) {
+          ret += " " + ident;
+        }
         ret += arrayAppendix;
       } else if (argument)
         ret += argument->toString();

languages/cpp/tests/test_cppcodecompletion.cpp

@@ -3101,6 +3101,8 @@ void TestCppCodeCompletion::testArgumentList()
   codeToArgList.insert("void foo(int arg[][1]){}", "(int arg[][1])");
   codeToArgList.insert("void foo(int arg[1][1]){}", "(int arg[1][1])");
   codeToArgList.insert("void foo(int arg[][1][1]){}", "(int arg[][1][1])");
+  codeToArgList.insert("void foo(void){}", "(void)");
+  codeToArgList.insert("void foo(int){}", "(int)");
   QMap< QByteArray, QString >::const_iterator it = codeToArgList.constBegin();
   while (it != codeToArgList.constEnd()){
     qDebug() << "input function is:" << it.key();