mdbx: add mdbx_malloc/mdbx_free, etc.

1 of 17 for https://github.com/leo-yuriev/libmdbx/issues/43

Change-Id: Ia5204be9f943fefde42e6a46e652c1be6ab6a96b

src/osal.h

@@ -105,6 +105,11 @@ typedef struct {
 typedef pthread_mutex_t mdbx_fastmutex_t;
 #endif /* Platform */
 
+#define mdbx_malloc malloc
+#define mdbx_calloc calloc
+#define mdbx_realloc realloc
+#define mdbx_free free
+
 /* *INDENT-OFF* */
 /* clang-format off */
 #if defined(HAVE_SYS_STAT_H) || __has_include(<sys/stat.h>)