StringRef'ize driver::ArgList::getArgString()

I’m thinking about StringRef’izing ArgList::getArgString(). Doing so would do away with several calls to strlen, but would not give any immediate performance benefits because the strings are stored in InputArgList in a SmallVector<const char*, 16> (typedef’d ‘ArgStringList’), and thus InputArgList::getArgString() must construct a StringRef from a const char* without knowing the length. The SmallVector could be changed to store StringRef’s, but this would slightly increase memory usage in InputArgList. Is it worth it to StringRef’ize ArgList::getArgString(), and further worth it to change the SmallVector in InputArgList to store StringRef’s?