This handy PHP Intellisense VS Code extension requires PHP 7 and up, so I finally decided to upgrade the onboard PHP on my Macbook Pro.
I used this: https://stackoverflow.com/questions/42537955/installing-php-using-homebrew-on-mac#42538097. (Earlier guides have instructions to run
brew tap… instructions that are no longer necessary. Not sure how tap deprecation happens but they were apparently moved into core homebrew?)
In the end it was as simple as
brew install php, which installed v7.2.6. I didn’t set Apache to run off it yet, though, since I don’t use the default MacOS web server anymore.