Change sleep to nanosleep to avoid failures.

The sleep function on arm 32 has points at which an unwind will fail since
the exidx information does not cover every possible pc. The nanosleep
function doesn't have this problem, it should unwind at all points.

Bug: 80314302

Test: Ran 137-cfi on target many times.
Change-Id: I6cdb8632a4e45f4cdd50f4c51a4f904eb5d2d340
diff --git a/test/137-cfi/cfi.cc b/test/137-cfi/cfi.cc
index 49db0c8..7ada47d 100644
--- a/test/137-cfi/cfi.cc
+++ b/test/137-cfi/cfi.cc
@@ -56,9 +56,12 @@
 
 extern "C" JNIEXPORT jboolean JNICALL Java_Main_sleep(JNIEnv*, jobject, jint, jboolean, jdouble) {
   // Keep pausing.
+  struct timespec ts = { .tv_sec = 100, .tv_nsec = 0 };
   printf("Going to sleep\n");
   for (;;) {
-    sleep(1);
+    // Use nanosleep since it gets to the system call quickly and doesn't
+    // have any points at which an unwind will fail.
+    nanosleep(&ts, nullptr);
   }
 }