Fix #75070: Opcache functions only apply to in-memory cache

Closes GH-1030.

reference/opcache/functions/opcache-get-status.xml

@@ -13,7 +13,8 @@
    <methodparam choice="opt"><type>bool</type><parameter>include_scripts</parameter><initializer>&true;</initializer></methodparam>
   </methodsynopsis>
   <para>
-   This function returns state information about the cache instance
+   This function returns state information about the in-memory cache instance. It will not return any
+   information about the file cache.
   </para>
  </refsect1>
 

reference/opcache/functions/opcache-invalidate.xml

@@ -17,7 +17,7 @@
    This function invalidates a particular script from the opcode cache. If
    <parameter>force</parameter> is unset or &false;, the script will only be
    invalidated if the modification time of the script is newer than the cached
-   opcodes.
+   opcodes. This function only invalidates in-memory cache and not file cache.
   </para>
  </refsect1>
 

reference/opcache/functions/opcache-is-script-cached.xml

@@ -15,6 +15,7 @@
   <para>
    This function checks if a PHP script has been cached in OPCache. This can be
    used to more easily detect the "warming" of the cache for a particular script.
+   This function only checks in-memory cache, not file cache.
   </para>
  </refsect1>
 

reference/opcache/functions/opcache-reset.xml

@@ -16,7 +16,8 @@
   <para>
    This function resets the entire opcode cache. After calling
    <function>opcache_reset</function>, all scripts will be reloaded and
-   reparsed the next time they are hit.
+   reparsed the next time they are hit. This function only resets
+   in-memory cache, not the file cache.
   </para>
  </refsect1>