merge revision(s) 40124: [Backport #8220]

	* compile.c (iseq_compile_each): fix of defined? with empty
	  expression.  [ruby-core:53999] [Bug #8220]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@40312 b2dd03c8-39d4-4d8f-98ff-823fe69b080e