Possible stack overshoot on visiting placeholder type if it is not deduced.

[kumarak]

While getting token provenance if the placeholder type is not deduced while visiting the types, It may call the visitor function on the same type causing recursion and stack overshoot. There should be a check added here if the placeholder type is deduced or not and then only call the visitor on deduced types.

https://github.com/trailofbits/multiplier/blob/main/bin/Index/Provenance.cpp#L317