Symbols like numbered parameters in block get syntax error #5295
Description
Example
$ bin/mruby -e 'p Array.new(1){:_1}'
-e:1:18: syntax error, unexpected tNUMPARAM$ ruby -e 'p Array.new(1){:_1}'
[:_1]{{ message }}
$ bin/mruby -e 'p Array.new(1){:_1}'
-e:1:18: syntax error, unexpected tNUMPARAM$ ruby -e 'p Array.new(1){:_1}'
[:_1]