Apply even more fixups

- Finish cleaning up the stdio unlocked APIs
- Make __cxa_finalize() properly thread safe
- Don't log locks if threads aren't being used
- Add some more mutex guards to places using _mmi
- Specific lock names now appear in the --ftrace logs
- Fix mkdeps.com generating invalid Makefiles sometimes
- Simplify and fix bugs in the test runner infrastructure
- Fix issue where sometimes some functions wouldn't be logged

libc/intrin/g_fds.c

@@ -27,7 +27,15 @@
 STATIC_YOINK("_init_g_fds");
 
 struct Fds g_fds;
-pthread_mutex_t __fds_lock_obj;
+static pthread_mutex_t __fds_lock_obj;
+
+void(__fds_lock)(void) {
+  pthread_mutex_lock(&__fds_lock_obj);
+}
+
+void(__fds_unlock)(void) {
+  pthread_mutex_unlock(&__fds_lock_obj);
+}
 
 textstartup void InitializeFileDescriptors(void) {
   struct Fds *fds;