Add spec for defined? with a literal array
Add compiler spec for defined? with array literals
Fix defined? with an array literal

This iterates over all elements in the Array and calls defined? on them.
Add a Enumerator#initialize spec for 2.1

Follow ruby/ruby#368
Add a Enumerator::Generator#initialize spec for 2.1

Follow r42234
Merge remote-tracking branch 'origin/master' into compiler

Conflicts:
	lib/compiler/ast/literals.rb