Workaround for the warning in nxt_realloc() on GCC 12.

This closes #639 issue on Github.

docs/changes.xml

@@ -31,6 +31,12 @@ NGINX Unit updated to 1.27.0.
          date="" time=""
          packager="Andrei Belov <defan@nginx.com>">
 
+<change type="feature">
+<para>
+compatibility with GCC 12.
+</para>
+</change>
+
 <change type="bugfix">
 <para>
 the controller process could crash when a chain with more than 4

src/nxt_malloc.c

@@ -65,16 +65,23 @@ void *
 nxt_realloc(void *p, size_t size)
 {
     void       *n;
+    uintptr_t  ptr;
+
+    /*
+     * Workaround for a warning on GCC 12 about using "p" pointer in debug log
+     * after realloc().
+     */
+    ptr = (uintptr_t) p;
 
     n = realloc(p, size);
 
     if (nxt_fast_path(n != NULL)) {
-        nxt_log_debug(nxt_malloc_log(), "realloc(%p, %uz): %p", p, size, n);
+        nxt_log_debug(nxt_malloc_log(), "realloc(%p, %uz): %p", ptr, size, n);
 
     } else {
         nxt_log_alert_moderate(&nxt_malloc_log_moderation, nxt_malloc_log(),
                                "realloc(%p, %uz) failed %E",
-                               p, size, nxt_errno);
+                               ptr, size, nxt_errno);
     }
 
     return n;