feat(crab): use macro to avoid crab infer 0 size allocation

Author: LinerSu

seahorn/lib/proof_allocators.c

@@ -13,14 +13,14 @@
 
 void *realloc(void *ptr, size_t new_size) { return sea_realloc(ptr, new_size); }
 
-void *bounded_malloc(size_t size) {
+void *bounded_malloc_havoc(size_t size) {
   #ifdef __CRAB__
   assume(size > 1);
   #endif
   return size == 0 ? NULL : sea_malloc_havoc_safe(size);
 }
 
-void *can_fail_malloc(size_t size) {
+void *can_fail_malloc_havoc(size_t size) {
   #ifdef __CRAB__
   assume(size > 1);
   #endif