parser: Tweak function parameter parsing to avoid rollback on succesfull path
parser: Tweak function parameter parsing to avoid rollback on succesfull path

graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,GBGamer/rust,graydon/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,graydon/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust