Properly handle "#void" in analysis server.

tests/corelib/symbol_reserved_word_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import "package:expect/expect.dart";
 
 void checkBadSymbol(String s) {
   Expect.throws(() => new Symbol(s), (e) => e is ArgumentError);
 }
 
 main() {
   var x;
 
   // 'void' is allowed as a symbol name.
   x = const Symbol('void');     /// 01: ok
   x = #void;                    /// 02: ok
   x = new Symbol('void');       /// 03: ok
 
   // However, it is not allowed as a part of a symbol name.
   x = const Symbol('void.foo'); /// 04: compile-time error
-  x = #void.foo;                /// 05: compile-time error
+  x = #void.foo;                /// 05: static type warning

[ahe, 2017/04/05 20:04:14]

What is supposed to happen when this line is executed?

[Paul Berry, 2017/04/05 20:29:28]

It should be equivalent to:

x = (#void).foo;

So it should produce a runtime error:

NoSuchMethodError: Class 'Symbol' has no instance getter 'foo'.

Gilad was supposed to update the spec so that the grammar rule for symbol would
be:

symbolLiteral:
  ‘#’ (void | operator | (identifier (‘.’ identifier)*))
  ;

But it looks like he never got around to it
(https://github.com/dart-lang/sdk/issues/20191 is still open).

In retrospect I used the wrong test expectation; it should have been:

x = #void.foo; /// 05: runtime error, static type warning

Or maybe this would have been clearer:

x = #void.hashCode; /// 05: ok

[ahe, 2017/04/06 10:55:52]

Thank you for the details. Based on them, I've changed it to:

Expect.throws(() { x = #void.foo; }, (e) => e is NoSuchMethodError); //# 05:
static type warning

In CL 2804843003.

[Paul Berry, 2017/04/06 17:20:55]

Sounds reasonable.  Thanks!

   checkBadSymbol('void.foo');   /// 06: ok
   x = const Symbol('foo.void'); /// 07: compile-time error
   x = #foo.void;                /// 08: compile-time error
   checkBadSymbol('foo.void');   /// 09: ok
 
   // All other reserved words are disallowed.
   x = const Symbol('assert');   /// 10: compile-time error
   x = const Symbol('break');    /// 10: continued
   x = const Symbol('case');     /// 10: continued
   x = const Symbol('catch');    /// 10: continued
@@ skipping 83 matching lines @@
   checkBadSymbol('super');      /// 12: continued
   checkBadSymbol('switch');     /// 12: continued
   checkBadSymbol('this');       /// 12: continued
   checkBadSymbol('throw');      /// 12: continued
   checkBadSymbol('true');       /// 12: continued
   checkBadSymbol('try');        /// 12: continued
   checkBadSymbol('var');        /// 12: continued
   checkBadSymbol('while');      /// 12: continued
   checkBadSymbol('with');       /// 12: continued
 }