Merge pull request #5436 from acozzette/fix-sched-yield

Removed configure check for sched_yield

configure.ac

diff --git a/configure.ac b/configure.ac
index 18a77f5..ec5cb1c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -205,15 +205,6 @@
 # We still keep this for improving pbconfig.h for unsupported platforms.
 AC_CXX_STL_HASH
 
-case "$target_os" in
-  mingw* | cygwin* | win* | aix* | *android* )
-    ;;
-  *)
-    # Need to link against rt on Solaris
-    AC_SEARCH_LIBS([sched_yield], [rt], [], [AC_MSG_FAILURE([sched_yield was not found on your system])])
-    ;;
-esac
-
 # Enable ObjC support for conformance directory on OS X.
 OBJC_CONFORMANCE_TEST=0
 case "$target_os" in