prepare_for_testing.
* gdb.fortran/multi-dim.exp: Use standard_testfile.
* gdb.fortran/module.exp: Use standard_testfile.
* gdb.fortran/logical.exp: Use standard_testfile.
* gdb.fortran/library-module.exp: Use standard_testfile,
standard_output_file.
* gdb.fortran/derived-type.exp: Use standard_testfile,
prepare_for_testing.
* gdb.fortran/complex.exp: Use standard_testfile,
prepare_for_testing.
* gdb.fortran/charset.exp: Use standard_testfile.
* gdb.fortran/array-element.exp: Use standard_testfile,
prepare_for_testing.