merge revision(s) 39282: [Backport #8007]

	* vm.c (ENV_IN_HEAP_P): fix off-by-one error.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39569 b2dd03c8-39d4-4d8f-98ff-823fe69b080e