[javascript parser proto fuzzer] Add tokens needed for private fields

Bug: v8:7193
Change-Id: I67da5487192d4a9bc4aa7a24fd340a7ed6e231a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2214882Reviewed-by: Jonathan Metzman <metzman@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#771704}

testing/libfuzzer/fuzzers/dicts/javascript_parser_proto.dict

@@ -61,6 +61,8 @@
 ">="
 "!"
 "~"
+"#"
+".#"
 
 # Keywords, contextual keywords, literals, reserved words.
 "__proto__"