yield in class body produces two SyntaxError outputs

[headius]

It's working, but why do we get two reports?

[] ~/work/jruby $ jruby -e 'class Foo; yield; end'
SyntaxError: -e:1: Invalid yield
SyntaxError: -e:1: Invalid yield

[] ~/work/jruby $ jruby -e 'class Foo; class << self; yield; end; end'
SyntaxError: -e:1: Invalid yield
SyntaxError: -e:1: Invalid yield

[headius]

Relates to 3.0 feature (#6878):

• yield in singleton class definitions in methods is now a SyntaxError
  instead of a warning. yield in a class definition outside of a method
  is now a SyntaxError instead of a LocalJumpError. [Feature #15575]