[clang-format] Handle unary operator overload with arguments and specifiers

[sugak]

Summary

Before:

int operator++(int)noexcept;

After:

int operator++(int) noexcept;

[djasper]

Looks good, thank you.

[sugak]

@djasper: would you accept and push this for me :)

[djasper]

Submitted as r317473. Thank you!

lib/Format/TokenAnnotator.cpp

       break;
     case tok::kw_operator:
       while (CurrentToken &&
              !CurrentToken->isOneOf(tok::l_paren, tok::semi, tok::r_paren)) {
         if (CurrentToken->isOneOf(tok::star, tok::amp))
           CurrentToken->Type = TT_PointerOrReference;
         consumeToken();
         if (CurrentToken &&
-            CurrentToken->Previous->isOneOf(TT_BinaryOperator, tok::comma))
+            CurrentToken->Previous->isOneOf(TT_BinaryOperator, TT_UnaryOperator,
+                                            tok::comma))
           CurrentToken->Previous->Type = TT_OverloadedOperator;
       }
       if (CurrentToken) {
         CurrentToken->Type = TT_OverloadedOperatorLParen;
         if (CurrentToken->Previous->is(TT_BinaryOperator))
           CurrentToken->Previous->Type = TT_OverloadedOperator;
       }
       break;

unittests/Format/FormatTest.cpp

 TEST_F(FormatTest, UnderstandsOverloadedOperators) {
   verifyFormat("bool operator<();");
   verifyFormat("bool operator>();");
   verifyFormat("bool operator=();");
   verifyFormat("bool operator==();");
   verifyFormat("bool operator!=();");
   verifyFormat("int operator+();");
   verifyFormat("int operator++();");
+  verifyFormat("int operator++(int) volatile noexcept;");
   verifyFormat("bool operator,();");
   verifyFormat("bool operator();");
   verifyFormat("bool operator()();");
   verifyFormat("bool operator[]();");
   verifyFormat("operator bool();");
   verifyFormat("operator int();");
   verifyFormat("operator void *();");
   verifyFormat("operator SomeType<int>();");