testsuite/93697 fix inconsistent warning in testcase

The warning was emitted inconsistently on targets, so disable it since
the testcase was for an ICE.

2020-02-12  Richard Biener  <rguenther@suse.de>

	PR testsuite/93697
	* gcc.dg/pr93661.c: Pass -w, remove dg-warning.

gcc/testsuite/ChangeLog

+2020-02-12  Richard Biener  <rguenther@suse.de>
+
+	PR testsuite/93697
+	* gcc.dg/pr93661.c: Pass -w, remove dg-warning.
+
 2020-02-11  David Malcolm  <dmalcolm@redhat.com>
 
 	PR analyzer/93288

gcc/testsuite/gcc.dg/pr93661.c

 /* { dg-do compile } */
-/* { dg-options "-O2" } */
+/* { dg-options "-O2 -w" } */
 
 int f ()
 {
   unsigned x = 0xffffffff;
-  __builtin_memset (1+(char *) &x, 0, -1); /* { dg-warning "maximum object size" } */
+  __builtin_memset (1+(char *) &x, 0, -1);
   return (x != 0xf0000000);
 }