[llvm] undo breaking changes from "Reduce AsmPrinterHandlers virt. fn calls" without reverting the performance gains (PR #122297)

[Alexis Engelke via llvm-commits]

aengelke wrote:

Looks generally fine, thanks for finding a way that doesn't seem to impact performance. (I put it up for llvm-compile-time-tracker for confirmation.)

I'm not quite happy with the naming, it should rather be AsmPrinterBasicHandler (AsmPrinter is the main class). Maybe WinCFGuard could inherit from the new AsmPrinterHandler, and instead of AsmBasicPrinterHandler we could just use and store EHStreamer? Also DebugHandlers is now a misleading name.

https://github.com/llvm/llvm-project/pull/122297