2001-06-08  Benjamin Kosnik  <bkoz@redhat.com>

	libstdc++/2767
	libstdc++/2989
	libstdc++/2992
	* include/std/*: Add copyright notice.
	* include/c_std/bits/*: Use using statements instead of extern "C".
	* include/c_std/bits/std_cmath.h: Don't overload double versions
	of math functions with __buitin versions, use global version to
	prevent ambiguities. Remove define hacks.
	* include/c_std/bits/std_cwchar.h: Using declarations for "C"
	functions that have changed signatures and std::
	declarations. Remove define hacks.
	* include/c_std/bits/std_cwchar.h: Same, plus remove ambiguous
	__builtins in std::. Remove define hacks.
	* testsuite/17_intro/headers_c.cc: Add tests.
	* testsuite/17_intro/headers_c++.cc: Add test.

From-SVN: r43061