ld: fix C23 issue in vers7 test

This test is UNSUPPORTED on arm64 with GCC 15 (which defaults to -std=gnu23)
because it now prototypes "no arguments".

	PR ld/32546
	* ld-elfvers/vers7.c: Fix function definitions for C23.

Author: thesamesam

ld/testsuite/ld-elfvers/vers7.c

@@ -2,8 +2,8 @@
  * Test program that goes with test7.so
  */
 
-extern int hide_a();
-extern int show_b();
+extern int hide_a(int e);
+extern int show_b(int e);
 
 int
 main()