Stacktrace and FatalErrorException problem

[sztyup]

Symfony and Laravel, and probably many other framework uses a Symfony\Component\Debug\Exception\FatalErrorException in its own Fatal error handling process before passing it to Sentry.
The problem is it doesn't return the stacktrace in a standard debug_backtrace format, but replaces the arguments array indexes to the name of the variable if using xdebug.
[args] => Array ( [0] => true )
becomes
[args] => Array ( [variableName] => true )
This causes Sentry\StackTrace::getFrameArgumentsValues function to emit a Warning: A non-numeric value encountered while processing the above Exception. This whole thing makes debugging much more difficult.
If you think this is not edge case enough to warrant a fix, i would be happy to start working on a PR.

[Jean85]

This is not an edge case for sure! We have a beta Laravel SDK in the works, and a Symfony one too.

Please proceed! Tests welcome, obviously!

[ste93cry]

Fixed in #763