Properly handle "#void" in analysis server.

tests/corelib/symbol_reserved_word_test.dart

Index: tests/corelib/symbol_reserved_word_test.dart
diff --git a/tests/corelib/symbol_reserved_word_test.dart b/tests/corelib/symbol_reserved_word_test.dart
index 7a61aab7e912eb30c2565712107d7a2b976b3b81..901fb34cd396b540804094f83f693b18c2c175be 100644
--- a/tests/corelib/symbol_reserved_word_test.dart
+++ b/tests/corelib/symbol_reserved_word_test.dart
@@ -18,7 +18,7 @@ main() {
 
   // 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