deps: partially revert commit `v1.11-512-geeee551'

deps: partially revert commit `v1.11-512-geeee551'

This change partly reverts commit "Create subdirs for generated
sources even when not dep tracking", of 2011-04-02.
That commit had caused the bugs #8485 and #8526.  Since we are
nearing the bug-fixing automake release 1.11.2, the safest policy
at the moment is to just revert the problematic hunks: an older,
known bug is better than a regression.

* automake.in (handle_single_transform): Don't add a dirstamp
dependency, even when $object is derived and lands in a subdir.
* tests/Makefile.am (XFAIL_TESTS): Add lex-subobj-nodep.test,
remove yacc-dist-nobuild-subdir.test.