[sparkplug] Drop TODO to inline fast ToString path

We could revisit this later, but right now the direction we're going is
simply keeping fast paths in the called builtins and not generating more
custom inline code.

Bug: v8:11429
Change-Id: I2e3a67e1a2a2ab62e8c785dd9bdf2de3e7215f60
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2695405
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72747}

src/baseline/baseline-compiler.cc

@@ -1672,7 +1672,6 @@ void BaselineCompiler::VisitToObject() {
 }
 
 void BaselineCompiler::VisitToString() {
-  // TODO(v8:11429,verwaest): Add fast inline path if it's already a string.
   CallBuiltin(Builtins::kToString, kInterpreterAccumulatorRegister);
 }