jrubyc broken for simple (self-executing) scripts in 9.1.7.0

[the-michael-toy]

We found this because we wrote a test case for #4445 which failed when we were investigating the possibility of moving from 9.1.5.0 to 9.1.7.0. You can't run jrubyc on even a trivial source input without getting this error

% rvm uninstall --gems jruby-9.1.7.0
% rvm install jruby-9.1.7.0
% rvm use jruby-9.1.7.0
% echo "42" > 42.rb
% jrubyc 42.rb
TypeError: failed to coerce org.objectweb.asm.ClassWriter to org.jruby.org.objectweb.asm.ClassVisitor
  block in compile_files_with_options at /Users/mtoy/.rvm/rubies/jruby-9.1.7.0/lib/ruby/stdlib/jruby/compiler.rb:189
  block in compile_files_with_options at /Users/mtoy/.rvm/rubies/jruby-9.1.7.0/lib/ruby/stdlib/jruby/compiler.rb:297
                                 each at org/jruby/RubyArray.java:1733
           compile_files_with_options at /Users/mtoy/.rvm/rubies/jruby-9.1.7.0/lib/ruby/stdlib/jruby/compiler.rb:281
                         compile_argv at /Users/mtoy/.rvm/rubies/jruby-9.1.7.0/lib/ruby/stdlib/jruby/compiler.rb:94
                               <main> at /Users/mtoy/.rvm/rubies/jruby-9.1.7.0/bin/jrubyc:5
% jruby -e "puts RUBY_DESCRIPTION"
jruby 9.1.7.0 (2.3.1) 2017-01-11 68056ae Java HotSpot(TM) 64-Bit Server VM 25.112-b16 on 1.8.0_112-b16 +jit [darwin-x86_64]

[kares]

hopefully not totally :) ... such simple self-executing scripts are less common to be jrubyc-iled.
but yeah this should be fixed and covered by the compiler specs.

[headius]

Delete lib/jruby-truffle.jar and this should work ok. It's picking up the non-shaded ASM classes from that jar.

JRuby 9.1.8.0 will no longer ship jruby-truffle, so this is fixed already.