testsuite: add function declarations for __xstat family

As the inline comment says - the declarations have been dropped with
glibc 2.32.9000, as a result the build throws a set of lovely warnings.

Inspired by umockdev, which bears the same license as this project.
https://github.com/martinpitt/umockdev/commit/f1b416400479d861deffb4c5a40422dcdf190e85

Signed-off-by: Emil Velikov <[email protected]>
Signed-off-by: Lucas De Marchi <[email protected]>
diff --git a/testsuite/path.c b/testsuite/path.c
index c1ae498..5a291b1 100644
--- a/testsuite/path.c
+++ b/testsuite/path.c
@@ -163,10 +163,17 @@
 	return _fn(p, flags);					\
 }
 
-/* wrapper template for __xstat family */
+/*
+ * wrapper template for __xstat family
+ * This family got deprecated/dropped in glibc 2.32.9000, but we still need
+ * to keep it for a while for programs that were built against previous versions
+ */
 #define WRAP_VERSTAT(prefix, suffix)			    \
 TS_EXPORT int prefix ## stat ## suffix (int ver,	    \
 			      const char *path,		    \
+	                      struct stat ## suffix *st);   \
+TS_EXPORT int prefix ## stat ## suffix (int ver,	    \
+			      const char *path,		    \
 	                      struct stat ## suffix *st)    \
 { \
 	const char *p;					    \