* acinclude.m4 (GLIBCXX_CHECK_SYSTEM_ERROR): Add ECANCELED for cygwin.
	* configure: Regenerate.
	* config/os/generic/error_constants.h: Guard.
	* testsuite/19_diagnostics/headers/system_error/
	types_std_c++0x.cc: Same.

From-SVN: r128307