[testsuite]: Fix gcc.c-torture/execute/pr48571-1.c (4 -> sizeof(int))

[Georg-Johann Lay]

This patch fixes magic number 4 and uses sizeof(int) instead so that the test
no more fails on int=16 platforms.  Successfully tested on AVR.

Johann

        * gcc.c-torture/execute/pr48571-1.c (bar): Use offsets sizeof(int) 
instead of 4.


Index: gcc.c-torture/execute/pr48571-1.c
===================================================================
--- gcc.c-torture/execute/pr48571-1.c   (revision 178527)
+++ gcc.c-torture/execute/pr48571-1.c   (working copy)
@@ -1,3 +1,5 @@
+#define S (sizeof (int))
+
 unsigned int c[624];
 void __attribute__((noinline))
 bar (void)
@@ -5,9 +7,9 @@ bar (void)
   unsigned int i;
   /* Obfuscated c[i] = c[i-1] * 2.  */
   for (i = 1; i < 624; ++i)
-    *(unsigned int *)((void *)c + (__SIZE_TYPE__)i * 4)
+    *(unsigned int *)((void *)c + (__SIZE_TYPE__)i * S)
        = 2 * *(unsigned int *)((void *)c + ((__SIZE_TYPE__)i +
-                                            ((__SIZE_TYPE__)-4)/4) * 4);
+                                            ((__SIZE_TYPE__)-S)/S) * S);
 }
 extern void abort (void);
 int