util: Add an aligned realloc function

Mesa has one of these in imports.h, so u_memory needs one as well. This
is the version from mesa ported.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3024>

src/util/u_memory.h

@@ -60,6 +60,7 @@ extern "C" {
 
 #define align_malloc(_size, _alignment) os_malloc_aligned(_size, _alignment)
 #define align_free(_ptr) os_free_aligned(_ptr)
+#define align_realloc(_ptr, _oldsize, _newsize, _alignment) os_realloc_aligned(_ptr, _oldsize, _newsize, _alignment)
 
 static inline void *
 align_calloc(size_t size, unsigned long alignment)