* include/experimental/bits/fs_ops.h
	(exists(const path&, error_code&)): Clear error if status is known
	(LWG 2725).
	(status(const path&, error_code&)): Handle EOVERFLOW.
	* testsuite/experimental/filesystem/operations/exists.cc: Test
	overload taking an error_code.

From-SVN: r241417