re PR libstdc++/67066 (libstdc++-v3/src/filesystem/dir.cc fails to compile with --enable-concept-checks)

	PR libstdc++/67066
	* doc/xml/manual/configure.xml (manual.intro.setup.configure): Add
	caveats for --enable-concept-checks. Improve link text.
	* doc/xml/manual/diagnostics.xml (std.diagnostics.concept_checking):
	Clarify caveats.
	* doc/html/*: Regenerate.
	* include/bits/stl_deque.h (deque): Only use concept checks in C++03.
	* include/bits/stl_stack.h (stack): Likewise.
	* include/bits/stl_vector.h (vector): Likewise.

From-SVN: r226984