Interrupt doesn't work in --single-threaded

[chrisseaton]

% jt --use jvm ruby --single-threaded --shared-objects-debug ~/xxx/class-variables/benchmarks.rb
Using Interpreted TruffleRuby: mxbuild/truffleruby-jvm
$ /Users/chrisseaton/src/github.com/Shopify/truffleruby/mxbuild/truffleruby-jvm/languages/ruby/bin/truffleruby \
  --experimental-options \
  --core-load-path=/Users/chrisseaton/src/github.com/Shopify/truffleruby/src/main/ruby/truffleruby \
  --single-threaded \
  --shared-objects-debug \
  /Users/chrisseaton/xxx/class-variables/benchmarks.rb
Warming up --------------------------------------
           ivar_read^C   203.966k i/100ms
                read^C   206.934k i/100ms
          class_read   211.044k i/100ms
       constant_read^C^C^C^C^C   205.141k i/100ms
               write   174.042k i/100ms
         class_write   172.514k i/100ms
                 get   127.420k i/100ms
                 set

[eregon]

Thanks for the report, can be reproduced with simply jt ruby --single-threaded -e 'p 1; sleep'

[eregon]

With the fix:

$ jt ruby --single-threaded -e 'p 1; sleep'
1
^C[ruby] SEVERE: signal SIGINT caught but can't create a thread to handle it so restoring the default handler and re-raising the signal
zsh: exit 130

The log message was not printed, and instead threw an exception but exceptions are ignored by the JVM when it calls the SignalHandler.