8008559: [parfait] Path through non-void function...

8008559: [parfait] Path through non-void function '_ZN2os15thread_cpu_timeEP6Thread' returns an undefined value
Summary: safety checks for non-Apple thread time functions
Reviewed-by: kvn

src/os/bsd/vm/os_bsd.cpp

@@ -3903,15 +3903,27 @@ bool os::pd_unmap_memory(char* addr, size_t bytes) {
 jlong os::current_thread_cpu_time() {
 #ifdef __APPLE__
   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
+#else
+  Unimplemented();
+  return 0;
 #endif
 }
 
 jlong os::thread_cpu_time(Thread* thread) {
+#ifdef __APPLE__
+  return os::thread_cpu_time(thread, true /* user + sys */);
+#else
+  Unimplemented();
+  return 0;
+#endif
 }
 
 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
 #ifdef __APPLE__
   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
+#else
+  Unimplemented();
+  return 0;
 #endif
 }
 
@@ -3935,6 +3947,9 @@ jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
   } else {
     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
   }
+#else
+  Unimplemented();
+  return 0;
 #endif
 }