* test/infra/android/test-controller.el (ats-run-test): Run
tests in a temp buffer.

* test/lisp/eshell/em-alias-tests.el (ert, em-alias)
(eshell-tests-helpers):

* test/lisp/eshell/em-basic-tests.el (em-basic)
(eshell-tests-helpers):

* test/lisp/eshell/em-cmpl-tests.el (em-unix)
(eshell-tests-helpers):

* test/lisp/eshell/em-dirs-tests.el (em-dirs)
(eshell-tests-helpers):

* test/lisp/eshell/em-extpipe-tests.el (ert-x)
(eshell-tests-helpers):

* test/lisp/eshell/em-glob-tests.el (ert, eshell-tests-helpers):

* test/lisp/eshell/em-hist-tests.el (eshell)
(eshell-tests-helpers):

* test/lisp/eshell/em-pred-tests.el (em-pred)
(eshell-tests-helpers):

* test/lisp/eshell/em-prompt-tests.el (em-prompt)
(eshell-tests-helpers):

* test/lisp/eshell/em-script-tests.el (em-script)
(eshell-tests-helpers):

* test/lisp/eshell/em-unix-tests.el (ert-x)
(eshell-tests-helpers):

* test/lisp/eshell/esh-arg-tests.el (eshell)
(eshell-tests-helpers):

* test/lisp/eshell/esh-cmd-tests.el (eshell)
(eshell-tests-helpers):

* test/lisp/eshell/esh-ext-tests.el (eshell)
(eshell-tests-helpers):

* test/lisp/eshell/esh-io-tests.el (eshell)
(eshell-tests-helpers):

* test/lisp/eshell/esh-mode-tests.el (em-prompt)
(eshell-tests-helpers):

* test/lisp/eshell/esh-proc-tests.el (em-prompt)
(eshell-tests-helpers):

* test/lisp/eshell/esh-util-tests.el (esh-util)
(eshell-tests-helpers):

* test/lisp/eshell/esh-var-tests.el (eshell)
(eshell-tests-helpers):

* test/lisp/eshell/eshell-tests.el (esh-mode)
(eshell-tests-helpers): Load `eshell-tests-helpers' from the
resource directory.

* test/lisp/eshell/resources/eshell-tests-helpers.el: Move from
`test/lisp/eshell'.