2012-08-13  Marc Glisse  <marc.glisse@inria.fr>

	PR libstdc++/54112
	* include/c_compatibility/complex.h: Undefine complex, always
	include system's complex.h if present.
	* testsuite/26_numerics/complex/c99.cc: New testcase.
	* testsuite/17_intro/headers/c++1998/complex.cc: Likewise.
	* doc/xml/manual/numerics.xml: Document it.

From-SVN: r190340