Add pthread_setschedprio.

Bug: http://b/26204555
Test: ran tests
Change-Id: Ic34062b9b6036a1ce2642a069514bab48a893338
diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index f342577..85978bd 100755
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -566,6 +566,18 @@
   EXPECT_EQ(ESRCH, pthread_setschedparam(null_thread, policy, &param));
 }
 
+TEST_F(pthread_DeathTest, pthread_setschedprio__no_such_thread) {
+  pthread_t dead_thread;
+  MakeDeadThread(dead_thread);
+
+  EXPECT_DEATH(pthread_setschedprio(dead_thread, 123), "invalid pthread_t");
+}
+
+TEST_F(pthread_DeathTest, pthread_setschedprio__null_thread) {
+  pthread_t null_thread = 0;
+  EXPECT_EQ(ESRCH, pthread_setschedprio(null_thread, 123));
+}
+
 TEST_F(pthread_DeathTest, pthread_join__no_such_thread) {
   pthread_t dead_thread;
   MakeDeadThread(dead_thread);
@@ -2147,3 +2159,12 @@
     ASSERT_EQ(0, munmap(pages[i], kPageSize));
   }
 }
+
+TEST(pthread, pthread_setschedparam) {
+  sched_param p = { .sched_priority = INT_MIN };
+  ASSERT_EQ(EINVAL, pthread_setschedparam(pthread_self(), INT_MIN, &p));
+}
+
+TEST(pthread, pthread_setschedprio) {
+  ASSERT_EQ(EINVAL, pthread_setschedprio(pthread_self(), INT_MIN));
+}