If you search for an exact match you still get almost 600 results, see:

https://github.com/search?q=%22eval%28%24_GET%22&type=Code&r...

I would definitely expect the google pattern of doing exact match when in quotes. Throw in a regexp engine as well, because I tried using wildcards and that didn't do anything.

For example, if searching for vulnerabilities I would like to be able to do something like:

  eval(.*$_[(GET|POST)].*)