[clang] [clang] Update argument checking tablegen code to use a 'full' name (PR #99993)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> This causes significant compile-time regressions, especially for unoptimized builds: https://llvm-compile-time-tracker.com/compare.php?from=39b6900852e7a1187bd742ba5c1387ca1be58e2c&to=2acf77f987331c05520c5bfd849326909ffce983&stat=instructions:u
> 
> You probably need to separately match the syntax and the name without constructing a temporary `std::string`.

Thank you for identifying this, @nikic!

> That should elimate the need for any new std::strings. @AaronBallman does this sound reasonable?

That seems like a good approach to me

https://github.com/llvm/llvm-project/pull/99993