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/fgetws.c

@@ -16,26 +16,25 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/assert.h"
-#include "libc/errno.h"
 #include "libc/stdio/stdio.h"
 
 /**
  * Reads UTF-8 content from stream into UTF-32 buffer.
+ *
+ * This function is similar to getline() except it'll truncate lines
+ * exceeding size. The line ending marker is included and may be removed
+ * using _chomp().
+ *
+ * @param s is is nul-terminated string that's non-null
+ * @param size is byte length of `s`
+ * @param f is file stream object pointer
+ * @see fgetws()
+ * @threadsafe
  */
-wchar_t *fgetws_unlocked(wchar_t *s, int size, FILE *f) {
-  wint_t c;
-  wchar_t *p = s;
-  if (size > 0) {
-    while (--size > 0) {
-      if ((c = fgetwc_unlocked(f)) == -1) {
-        if (ferror_unlocked(f) == EINTR) continue;
-        break;
-      }
-      *p++ = c;
-      if (c == '\n') break;
-    }
-    *p = '\0';
-  }
-  return (intptr_t)p > (intptr_t)s ? s : NULL;
+wchar_t *fgetws(wchar_t *s, int size, FILE *f) {
+  wchar_t *rc;
+  flockfile(f);
+  rc = fgetws_unlocked(s, size, f);
+  funlockfile(f);
+  return rc;
 }