When creating a symbolic link JRuby give bad error message when not an admin on windows

[cshupp1]

This issue is closely related to issue:
#4669

On today's build (and many previous release versions) when making a symlink in a non admin shell you get a poor error message. Consider:

>  java -jar C:\work\va-ctt\jruby\jruby\maven\jruby-complete\target\jruby-complete-9.1.13.0-SNAPSHOT.jar -S jirb                         
irb(main):001:0> File.symlink('c:\temp\del.me', 'c:\temp\del2.me')                                                                       
SystemCallError: Unknown error (SystemCallError) 1314 - CreateSymbolicLink                                                               
        from uri:classloader:/jruby/kernel/file.rb:115:in `symlink'                                                                      
        from (irb):1:in `<eval>'                                                                                                         
        from org/jruby/RubyKernel.java:1000:in `eval'                                                                                    
        from org/jruby/RubyKernel.java:1298:in `loop'                                                                                    
        from org/jruby/RubyKernel.java:1120:in `catch'                                                                                   
        from org/jruby/RubyKernel.java:1120:in `catch'                                                                                   
        from uri:classloader:/META-INF/jruby.home/bin/jirb:13:in `<main>'                                                                

MRI ruby will give:

irb(main):003:0> File.symlink('c:\temp\del.me', 'c:\temp\del2.me')
Errno::EACCES: Permission denied @ rb_file_s_symlink - (c:\temp\del.me, c:\temp\del2.me)
        from (irb):3:in `symlink'
        from (irb):3
        from c:/languages/ruby/Ruby24-x64/bin/irb.cmd:19:in `<main>'

React on Rails makes use of these APIs and it would be nice to get a useful error message in the build to clue the developer in to run the build as an admin.

Thanks,
Cris