feat(newlib): Adds flockfile/funlockfile for safe multi-line printing

for printf, vprintf, etc.

Closes https://github.com/espressif/esp-idf/issues/2565

components/newlib/flockfile.c

@@ -0,0 +1,32 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdio.h>
+
+#include <sys/lock.h>
+#include <sys/reent.h>
+
+void flockfile(FILE *fp)
+{
+    if (fp && !(fp->_flags & __SSTR)) {
+        __lock_acquire_recursive(fp->_lock);
+    }
+}
+
+int ftrylockfile(FILE *fp)
+{
+    if (fp && !(fp->_flags & __SSTR)) {
+        return __lock_try_acquire_recursive(fp->_lock);
+    }
+    return 0;
+}
+
+void funlockfile(FILE *fp)
+{
+    if (fp && !(fp->_flags & __SSTR)) {
+        __lock_release_recursive(fp->_lock);
+    }
+}