./configure
$MAKE check
test -f ok
-EXEEXT=.bin $MAKE -e print-tests >stdout || { cat stdout; exit 1; }
-cat stdout
+run_make -O EXEEXT=.bin print-tests
$FGREP 'BEG: one.bin two.bin :END' stdout
# No am__EXEEXT_* variable is needed.
grep '_EXEEXT_[1-9]' Makefile.in && exit 1