Improve the efficiency of trace stitching

From the way benchmarks have been responding to recent PRs, it certainly seems like side exits could be made more efficient, especially in the happy path. This is especially true of _DYNAMIC_EXIT, which needs to do quite a bit of work for a successful stitch... perhaps the best option here is to just reduce the number of _DYNAMIC_EXITs that we run.

This could also include recompiling stitched traces together into the same executor to essentially remove stitching overhead, too.

Linked PRs

• gh-122295

L’issue non nomina file o test. Inizia esaminando le risposte dei benchmark e il percorso di trace-stitching attorno a _DYNAMIC_EXIT; determina se sia praticabile ridurre i dynamic exits o ricompilare gli stitched traces. Il lavoro è completato quando viene dimostrata una riduzione dell’overhead di stitching sui benchmark pertinenti.