Solaris 10 has sched_yield() in libc

auto/os/solaris

diff --git a/auto/os/solaris b/auto/os/solaris
index f98c851..333f0ae 100644
--- a/auto/os/solaris
+++ b/auto/os/solaris
@@ -7,14 +7,14 @@
 CORE_INCS="$UNIX_INCS"
 CORE_DEPS="$UNIX_DEPS $SOLARIS_DEPS"
 CORE_SRCS="$UNIX_SRCS $SOLARIS_SRCS "
-CORE_LIBS="$CORE_LIBS -lsocket -lnsl -lrt"
+CORE_LIBS="$CORE_LIBS -lsocket -lnsl"
 
 NGX_RPATH=YES
 
 # Solaris's make does not support a blank line between target and rules
 ngx_spacer=
 
-CC_AUX_FLAGS="$CC_AUX_FLAGS -D_FILE_OFFSET_BITS=64 -lsocket -lnsl -lrt"
+CC_AUX_FLAGS="$CC_AUX_FLAGS -D_FILE_OFFSET_BITS=64 -lsocket -lnsl"
 
 
 if [ $ZLIB_ASM != NO ]; then

auto/unix

diff --git a/auto/unix b/auto/unix
index 447b0e2..399e54c 100755
--- a/auto/unix
+++ b/auto/unix
@@ -173,6 +173,18 @@
 . auto/feature
 
 
+if [ $ngx_found != yes ]; then
+
+    ngx_feature="sched_yield() in librt"
+    ngx_feature_libs="-lrt"
+    . auto/feature
+
+    if [ $ngx_found = yes ]; then
+        CORE_LIBS="$CORE_LIBS -lrt"
+    fi
+fi
+
+
 ngx_feature="mmap(MAP_ANON|MAP_SHARED)"
 ngx_feature_name="NGX_HAVE_MAP_ANON"
 ngx_feature_run=yes