Ensure configure test compiler turds are removed.

This particular test can leave various <foo>.mod files in the OMPI top
build dir, which leads developers to say "what are these .mod files in
my 'svn status' output?".

So make a subdir, run the tests in there, and then remove the subdir.

Reviewed by Dave Goodell.

This is not 100% necessary for OMPI 1.7.4, but it would be nice.  The
goal is to have this test removed by OMPI 1.7.5 (i.e., fix ticket
4157).  So I leave it up to the RM to decide whether this goes into
1.7.4 or not.

cmr=v1.7.4:reviewer=ompi-rm1.7

This commit was SVN r30524.

config/ompi_fortran_check_ticket_4157.m4

@@ -18,6 +18,9 @@ AC_DEFUN([OMPI_FORTRAN_CHECK_TICKET_4157],[
 
     AC_CACHE_CHECK([for ticket 4157 issues], ticket_4157_var,
        [AC_LANG_PUSH([Fortran])
+        rm -rf conftest.$$.d
+        mkdir conftest.$$.d
+        cd conftest.$$.d
         AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
 MODULE MY_ABSTRACT_MODULE
   ABSTRACT INTERFACE
@@ -91,6 +94,8 @@ END PROGRAM TEST_ABSTRACT_PROCEDURE
              [AS_VAR_SET(ticket_4157_var, happy)],
              [AS_VAR_SET(ticket_4157_var, unhappy)])
         AC_LANG_POP([Fortran])
+        cd ..
+        rm -rf contest.$$.d
        ])
 
     AS_VAR_IF(ticket_4157_var, [happy], [$1], [$2])