Avoid abort() in test/integration/cpp/infallible_new_true.

Allow setting the safety check abort hook through mallctl, which avoids abort()
and core dumps.

include/jemalloc/internal/safety_check.h

@@ -4,8 +4,11 @@
 void safety_check_fail_sized_dealloc(bool current_dealloc, const void *ptr,
     size_t true_size, size_t input_size);
 void safety_check_fail(const char *format, ...);
+
+typedef void (*safety_check_abort_hook_t)(const char *message);
+
 /* Can set to NULL for a default. */
-void safety_check_set_abort(void (*abort_fn)(const char *));
+void safety_check_set_abort(safety_check_abort_hook_t abort_fn);
 
 JEMALLOC_ALWAYS_INLINE void
 safety_check_set_redzone(void *ptr, size_t usize, size_t bumped_usize) {