testsuite: suppress cast warnings in pr100563.c [PR100563]

Fix a warning when building on machines that don't have 32-bit pointers

gcc/testsuite:

	PR target/100563
	* gcc.dg/pr100563.c (dg-options): Add -wno-pointer-to-int-cast.

gcc/testsuite/gcc.dg/pr100563.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-Og" } */
+/* { dg-options "-Og -Wno-pointer-to-int-cast" } */
 unsigned long long e(void);
 void f(int);
 void a() {