Don't test for sched_yield on Windows
diff --git a/configure.ac b/configure.ac
index 3b5cb60..ba408af 100644
--- a/configure.ac
+++ b/configure.ac
@@ -139,8 +139,14 @@
ACX_PTHREAD
AC_CXX_STL_HASH
-# Need to link against rt on Solaris
-AC_SEARCH_LIBS([sched_yield], [rt], [], [AC_MSG_FAILURE([sched_yield was not found on your system])])
+case "$target_os" in
+ mingw* | cygwin* | win*)
+ ;;
+ *)
+ # Need to link against rt on Solaris
+ AC_SEARCH_LIBS([sched_yield], [rt], [], [AC_MSG_FAILURE([sched_yield was not found on your system])])
+ ;;
+esac
# HACK: Make gtest's configure script pick up our copy of CFLAGS and CXXFLAGS,
# since the flags added by ACX_CHECK_SUNCC must be used when compiling gtest
