[clang] [clang][rtsan] Introduce realtime sanitizer codegen and driver (PR #102622)

[Chris Apple via cfe-commits]

================
@@ -995,6 +996,13 @@ void EmitAssemblyHelper::RunOptimizationPipeline(
             FPM.addPass(BoundsCheckingPass());
           });
 
+    if (LangOpts.Sanitize.has(SanitizerKind::Realtime))
+      PB.registerScalarOptimizerLateEPCallback(
----------------
cjappl wrote:

I am completely not sure where in the pipeline this pass should live. Any advice from someone with more experience would be great. This was chosen to match other passes of sanitizers around it.

https://github.com/llvm/llvm-project/pull/102622