Make Filesystem TS tests pass in C++17 mode

Make Filesystem TS tests pass in C++17 mode

The <testsuite_fs.h> header defaults to using std::filesystem in C++17
mode. The Filesystem TS tests need to define the macro that causes
std::experimental::filesystem to be used instead.

	* testsuite/experimental/filesystem/file_status/1.cc: Add
	-DUSE_FILESYSTEM_TS to dg-options.
	* testsuite/experimental/filesystem/iterators/directory_iterator.cc:
	Likewise.
	* testsuite/experimental/filesystem/iterators/pop.cc: Likewise.
	* testsuite/experimental/filesystem/iterators/
	recursive_directory_iterator.cc: Likewise.
	* testsuite/experimental/filesystem/operations/absolute.cc: Likewise.
	* testsuite/experimental/filesystem/operations/canonical.cc: Likewise.
	* testsuite/experimental/filesystem/operations/copy.cc: Likewise.
	* testsuite/experimental/filesystem/operations/copy_file.cc: Likewise.
	* testsuite/experimental/filesystem/operations/create_directories.cc:
	Likewise.
	* testsuite/experimental/filesystem/operations/create_directory.cc:
	Likewise.
	* testsuite/experimental/filesystem/operations/create_symlink.cc:
	Likewise.
	* testsuite/experimental/filesystem/operations/current_path.cc:
	Likewise.
	* testsuite/experimental/filesystem/operations/equivalent.cc: Likewise.
	* testsuite/experimental/filesystem/operations/exists.cc: Likewise.
	* testsuite/experimental/filesystem/operations/file_size.cc: Likewise.
	* testsuite/experimental/filesystem/operations/is_empty.cc: Likewise.
	* testsuite/experimental/filesystem/operations/last_write_time.cc:
	Likewise.
	* testsuite/experimental/filesystem/operations/permissions.cc:
	Likewise.
	* testsuite/experimental/filesystem/operations/read_symlink.cc:
	Likewise.
	* testsuite/experimental/filesystem/operations/remove.cc: Likewise.
	* testsuite/experimental/filesystem/operations/remove_all.cc: Likewise.
	* testsuite/experimental/filesystem/operations/status.cc: Likewise.
	* testsuite/experimental/filesystem/operations/temp_directory_path.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/append/path.cc: Likewise.
	* testsuite/experimental/filesystem/path/assign/assign.cc: Likewise.
	* testsuite/experimental/filesystem/path/assign/copy.cc: Likewise.
	* testsuite/experimental/filesystem/path/compare/compare.cc: Likewise.
	* testsuite/experimental/filesystem/path/compare/path.cc: Likewise.
	* testsuite/experimental/filesystem/path/compare/strings.cc: Likewise.
	* testsuite/experimental/filesystem/path/concat/path.cc: Likewise.
	* testsuite/experimental/filesystem/path/concat/strings.cc: Likewise.
	* testsuite/experimental/filesystem/path/construct/copy.cc: Likewise.
	* testsuite/experimental/filesystem/path/construct/default.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/construct/locale.cc: Likewise.
	* testsuite/experimental/filesystem/path/construct/range.cc: Likewise.
	* testsuite/experimental/filesystem/path/construct/string_view.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/decompose/extension.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/decompose/filename.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/decompose/parent_path.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/decompose/relative_path.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/decompose/root_directory.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/decompose/root_name.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/decompose/root_path.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/decompose/stem.cc: Likewise.
	* testsuite/experimental/filesystem/path/generic/generic_string.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/itr/traversal.cc: Likewise.
	* testsuite/experimental/filesystem/path/modifiers/clear.cc: Likewise.
	* testsuite/experimental/filesystem/path/modifiers/make_preferred.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/modifiers/remove_filename.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/modifiers/replace_extension.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/modifiers/replace_filename.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/modifiers/swap.cc: Likewise.
	* testsuite/experimental/filesystem/path/native/string.cc: Likewise.
	* testsuite/experimental/filesystem/path/nonmember/hash_value.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/query/empty.cc: Likewise.
	* testsuite/experimental/filesystem/path/query/has_extension.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/query/has_filename.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/query/has_parent_path.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/query/has_relative_path.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/query/has_root_directory.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/query/has_root_name.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/query/has_root_path.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/query/has_stem.cc: Likewise.
	* testsuite/experimental/filesystem/path/query/is_relative.cc:
	Likewise.

From-SVN: r259396