[ownership] Split ownership lowering in the pass pipeline for non-transparent stdlib vs non-stdlib functions.

I am going to be moving back ownership lowering first in the stdlib so that we
can bring up the optimizer on ownership without needing to deal with
serialization issues (the stdlib doesn't deserialize SIL from any other
modules).

This patch just begins the mechanical process with a nice commit message. Should
be NFC.

Author: gottesmm

lib/SILOptimizer/PassManager/PassPipeline.cpp

@@ -436,7 +436,17 @@ static void addPerfEarlyModulePassPipeline(SILPassPipelinePlan &P) {
   // not blocked by any other passes' optimizations, so do it early.
   P.addDifferentiabilityWitnessDevirtualizer();
 
-  // Strip ownership from non-transparent functions.
+  // Strip ownership from non-transparent functions when we are not compiling
+  // the stdlib module. When compiling the stdlib, we eliminate ownership on
+  // these functions later with a nromal call to
+  // P.addNonTransparentFunctionOwnershipModelEliminator().
+  //
+  // This is done so we can push ownership through the pass pipeline first for
+  // the stdlib and then everything else.
+  P.addNonStdlibNonTransparentFunctionOwnershipModelEliminator();
+
+  // We earlier eliminated ownership if we are not compiling the stdlib. Now
+  // handle the stdlib functions.
   P.addNonTransparentFunctionOwnershipModelEliminator();
 
   // Start by linking in referenced functions from other modules.