Fix several test failures on Cygwin and MinGW.

Fix several test failures on Cygwin and MinGW.
* tests/nonrecursive.at: Use -no-undefined for foo.la.
* tests/recursive.at: Likewise.
* tests/subproject.at: Likewise.
* tests/lt_dladvise.at: For systems where undefined symbols are
not allowed, to not try to load the module libdepend.
[ mingw ]: Add to list of such systems.
* tests/testsuite.at (_LT_AT_TRANSLATE_TEXT_OUTPUT): New macro,
to translate line ending of expout and experr files suitable for
host executables.
(LT_AT_CHECK, LT_AT_NOINST_EXEC_CHECK): Use it.
Report by Bob Friesenhahn.