Build io-console extension by default

ruby/io-console#71

Author: kateinoigakukun

lib/ruby_wasm/packager.rb

@@ -79,7 +79,7 @@ def features
   end
 
   ALL_DEFAULT_EXTS =
-    "cgi/escape,continuation,coverage,date,digest/bubblebabble,digest,digest/md5,digest/rmd160,digest/sha1,digest/sha2,etc,fcntl,json,json/generator,json/parser,objspace,pathname,psych,rbconfig/sizeof,ripper,stringio,strscan,monitor,zlib,openssl"
+    "cgi/escape,continuation,coverage,date,digest/bubblebabble,digest,digest/md5,digest/rmd160,digest/sha1,digest/sha2,etc,fcntl,json,json/generator,json/parser,objspace,pathname,psych,rbconfig/sizeof,ripper,stringio,strscan,monitor,zlib,openssl,io/console"
 
   # Retrieves the build options used for building Ruby itself.
   def build_options