- provide a hidden_def for fputc_unlocked that is aliased to __fputc_unlocked.

  Fixes undefined references to __fputc_unlocked when calling fputc().

libc/stdio/fputc.c

@@ -72,7 +72,9 @@ int __fputc_unlocked(int c, register FILE *stream)
 }
 libc_hidden_def(__fputc_unlocked)
 
+libc_hidden_proto(fputc_unlocked)
 strong_alias(__fputc_unlocked,fputc_unlocked)
+libc_hidden_def(fputc_unlocked)
 
 libc_hidden_proto(putc_unlocked)
 strong_alias(__fputc_unlocked,putc_unlocked)