Bug in Hash literals with invalid symbol keys

[nirvdrum]

While looking at some IRB test failures with @st0012, we came across a case where MRI raises an EncodingError but TruffleRuby raises nothing. Looking quickly at the specs, I didn't see anything in the language specs to test this behavior. The code in question is a Hash literal with a symbol key with an invalid encoding.

puts({"\xAE": 1}.keys)

Note, I didn't print the Hash directly because the invalid key will raise a separate exception on TruffleRuby when calling Hash#inspect.

On MRI:

> ruby -v bad_irb.rb
ruby 3.2.0 (2022-12-25 revision a528908271) [arm64-darwin21.5.0]
bad_irb.rb: invalid symbol in encoding UTF-8 :"\xAE" (EncodingError)

On TruffleRuby:

> jt ruby -v bad_irb.rb
truffleruby 23.0.0-dev-8bb04d8c, like ruby 3.1.3, GraalVM CE JVM [aarch64-darwin]
�

[andrykonchin]

Fixed in 145d23e