Test fscanf of long double without <stdio.h>

Add a test for fscanf of long double without including <stdio.h>.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>

stdio-common/Makefile

@@ -193,6 +193,7 @@ tests := \
   scanf18 \
   scanf19 \
   temptest \
+  test-fscanf \
   test-fseek \
   test-fwrite \
   test-popen \

stdio-common/test-fscanf.c

@@ -0,0 +1,37 @@
+/* Test fscanf of long double without <stdio.h>.
+   Copyright (C) 2024 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <string.h>
+
+struct FILE;
+extern struct FILE *stdin;
+extern int fscanf (struct FILE *, const char *, ...);
+
+int
+main (void)
+{
+  int n, i;
+  long double x;
+  char name[50];
+  n = fscanf (stdin, "%d%Lf%s", &i, &x, name);
+
+  if (n != 3 || i != 25 || x != 24.5 || strcmp (name, "thompson"))
+    return 1;
+
+  return 0;
+}

stdio-common/test-fscanf.input

@@ -0,0 +1 @@
+25 24.5 thompson