[clang-repl] Correctly disambiguate dtor declarations from statements

[v.g.vassilev]

Let's rely on a post-commit review here.

[aaron.ballman]

clang/lib/Parse/ParseTentative.cpp

91

Are you sure you can remove this? Wouldn't this be used for a case like:

struct Foo {
  struct Bar {
    struct Baz {
      ~Baz();
    };
  };
};

Foo::Bar::Baz::~Baz() {}

(I could be reading the code wrong, but I thought we had a reason to check for annot_cxxscope -- seems we missed test coverage for it!)

[v.g.vassilev]

clang/lib/Parse/ParseTentative.cpp

91

It looks like we do not need the annot_cxxscope as it seems it was processed above (likely one of the recent additions such as ParseOptionalCXXScopeSpecifier). I added a test case for the case you proposed in rG87ae74692456

[aaron.ballman]

clang/lib/Parse/ParseTentative.cpp

91

Ah, good to know, and thank you for the additional test case!

clang/lib/Parse/ParseTentative.cpp

if (DisambiguatingWithExpression) {
                                       isDeductionGuide,
                                       DeclSpec::FriendSpecified::No))
             return true;
         }
         break;
       }
       case tok::kw_operator:
         return true;
-      case tok::annot_cxxscope: // Check if this is a dtor.
-        if (NextToken().is(tok::tilde))
-          return true;
-        break;
+      case tok::tilde:
       default:
         break;
       }
     }
   }
     [[fallthrough]];
     // simple-declaration
   default:

clang/test/Interpreter/disambiguate-decl-stmt.cpp

 S1::operator int() { return 0; }
 
 // Dtors
 using I = int;
 I x = 10;
 x.I::~I();
 x = 20;
 
+struct Dtor1 {~Dtor1();};
+Dtor1::~Dtor1() { printf("Dtor1\n"); }
+Dtor1 d1;
+
 // Ctors
 
 // Deduction guide
 template<typename T> struct A { A(); A(T); };
 A() -> A<int>;
 
 struct S2 { S2(); };
 S2::S2() = default;