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/stdio/fseeko.c

@@ -16,11 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/calls/calls.h"
-#include "libc/errno.h"
-#include "libc/stdio/internal.h"
 #include "libc/stdio/stdio.h"
-#include "libc/sysv/consts/o.h"
 
 /**
  * Repositions open file stream.
@@ -34,46 +30,12 @@
  * @param offset is the byte delta
  * @param whence can be SEET_SET, SEEK_CUR, or SEEK_END
  * @returns 0 on success or -1 on error
+ * @threadsafe
  */
-int fseeko_unlocked(FILE *f, int64_t offset, int whence) {
-  int res;
-  ssize_t rc;
-  int64_t pos;
-  if (f->fd != -1) {
-    if (__fflush_impl(f) == -1) return -1;
-    if (whence == SEEK_CUR && f->beg < f->end) {
-      offset -= f->end - f->beg;
-    }
-    if (lseek(f->fd, offset, whence) != -1) {
-      f->beg = 0;
-      f->end = 0;
-      res = 0;
-    } else {
-      f->state = errno == ESPIPE ? EBADF : errno;
-      res = -1;
-    }
-  } else {
-    switch (whence) {
-      case SEEK_SET:
-        pos = offset;
-        break;
-      case SEEK_CUR:
-        pos = f->beg + offset;
-        break;
-      case SEEK_END:
-        pos = f->end + offset;
-        break;
-      default:
-        pos = -1;
-        break;
-    }
-    if (0 <= pos && pos <= f->end) {
-      f->beg = pos;
-      res = 0;
-    } else {
-      f->state = errno = EINVAL;
-      res = -1;
-    }
-  }
-  return res;
+int fseeko(FILE *f, int64_t offset, int whence) {
+  int rc;
+  flockfile(f);
+  rc = fseeko_unlocked(f, offset, whence);
+  funlockfile(f);
+  return rc;
 }