exposes macOs malloc_good_size (#538)

src/snmalloc/override/malloc.cc

@@ -61,6 +61,12 @@ extern "C"
     return ThreadAlloc::get().alloc_size(ptr);
   }
 
+  SNMALLOC_EXPORT
+  size_t SNMALLOC_NAME_MANGLE(malloc_good_size)(size_t size)
+  {
+    return round_size(size);
+  }
+
   SNMALLOC_EXPORT void* SNMALLOC_NAME_MANGLE(realloc)(void* ptr, size_t size)
   {
     auto& a = ThreadAlloc::get();

src/test/func/malloc/malloc.cc

@@ -32,7 +32,7 @@ void check_result(size_t size, size_t align, void* p, int err, bool null)
     failed = true;
   }
   const auto alloc_size = our_malloc_usable_size(p);
-  auto expected_size = round_size(size);
+  auto expected_size = our_malloc_good_size(size);
 #ifdef SNMALLOC_PASS_THROUGH
   // Calling system allocator may allocate a larger block than
   // snmalloc. Note, we have called the system allocator with