Code inspection doesn't seem to find all php deprecated items

I'm trying out the product right now to see if it can help me migrate code from a PHP 5.3 environment to a newer PHP 7 environment.  Over the years we've had various people and none have updated the code, now they are gone and I'm stuck with it landing on my plate.

I know for a fact there is deprecated code like $HTTP_SERVER_VARS and $HTTP_POST_VARS in use, but so far I haven't been able to get PhpStorm to flag any of those.

I've tried setting the PHP Language Level to 7.0, 7.1, 7.2 and it doesn't flag those known items.  I do not have the PHP Composer synchronizing the IDE settings with composer.json that option is unchecked.

I've tried Run Inspection by Name and used Language Level, I just get a result of "No suspicious code found".

When doing a normal Inspect Code, it finds some PHP General Deprecated items, but those are mainly mysql database functions...neither of the ones I named above show up.

Am I doing something wrong?  Do I need to set the PHP Language Level to something like 5.5 first?

I'd like to be able to use a tool like this to help, rather than sit there looking at my Apache error log and loading pages and waiting to see a Deprecated entry show up in an error log...and then fixing that, and doing it again to try and identify all of these items.

Thanks,

Scott