merge revision(s) 39806: [Backport #8118]

	* vm_exec.c: Correct predefined macro name. This typo is introduced by
	  r36534 and should be backported to ruby_2_0_0.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39954 b2dd03c8-39d4-4d8f-98ff-823fe69b080e