Allow #[] and #[]= symbols.

sdk/lib/_internal/compiler/implementation/scanner/scanner.dart

Index: sdk/lib/_internal/compiler/implementation/scanner/scanner.dart
diff --git a/sdk/lib/_internal/compiler/implementation/scanner/scanner.dart b/sdk/lib/_internal/compiler/implementation/scanner/scanner.dart
index f74e339dacf807912659ee1fb7a801e333aa9383..34cac3a3bacd90757908e5b226a6eba60fa75a7d 100644
--- a/sdk/lib/_internal/compiler/implementation/scanner/scanner.dart
+++ b/sdk/lib/_internal/compiler/implementation/scanner/scanner.dart
@@ -436,8 +436,8 @@ abstract class AbstractScanner implements Scanner {
     next = advance();
     if (identical(next, $CLOSE_SQUARE_BRACKET)) {
       Token token = previousToken();
-      if (token is KeywordToken &&
-          identical(token.keyword.syntax, 'operator')) {
+      if (token is KeywordToken && token.keyword.syntax == 'operator' ||
+          token is SymbolToken && token.info == HASH_INFO) {
         return select($EQ, INDEX_EQ_INFO, INDEX_INFO);
       }
     }