gcc
	PR target/18997
	* config/i386/cygwin.h (GTHREAD_USE_WEAK): Define to 0.

libstdc++-v3
	PR target/18997
	* config/os/newlib/os_defines.h (_GLIBCXX_GTHREAD_USE_WEAK):
	Define to 0 for __CYGWIN__.

From-SVN: r92281