Update documentation of opcache.interned_strings_buffer (#4061)

Author: arnaud-lb

reference/opcache/ini.xml

@@ -421,7 +421,15 @@
     <listitem>
      <para>
       The amount of memory used to store interned strings, in megabytes.
+      The maximum value is 32767 on 64bit architectures,
+      and 4095 on 32bit architectures.
      </para>
+     <note>
+      <simpara>
+       Prior to PHP 8.4.0, the maximum value was 4095 megabytes on all
+       architectures.
+      </simpara>
+     </note>
     </listitem>
    </varlistentry>
    <varlistentry xml:id="ini.opcache.max-accelerated-files">