8245833: crash_with_sigfpe uses pthread_kill(SIGFPE) on macOS

Changed division code to ensure that real crash happens

Reviewed-by: dholmes

src/hotspot/share/utilities/vmError.cpp

@@ -1739,18 +1739,22 @@ bool VMError::check_timeout() {
 
 #ifndef PRODUCT
 typedef void (*voidfun_t)();
+
 // Crash with an authentic sigfpe
+volatile int sigfpe_int = 0;
 static void crash_with_sigfpe() {
+
   // generate a native synchronous SIGFPE where possible;
+  sigfpe_int = sigfpe_int/sigfpe_int;
+
   // if that did not cause a signal (e.g. on ppc), just
   // raise the signal.
-  volatile int x = 0;
-  volatile int y = 1/x;
 #ifndef _WIN32
   // OSX implements raise(sig) incorrectly so we need to
   // explicitly target the current thread
   pthread_kill(pthread_self(), SIGFPE);
 #endif
+
 } // end: crash_with_sigfpe
 
 // crash with sigsegv at non-null address.