[existential-specializer] Do not process callees with ownership as well as callers without ownership.

I already turned this off for callers. I just didn't do it for callees. Just an
oversight.

rdar://57291312

Author: gottesmm

lib/SILOptimizer/FunctionSignatureTransforms/ExistentialSpecializer.cpp

@@ -207,7 +207,6 @@ bool ExistentialSpecializer::canSpecializeExistentialArgsInFunction(
 
 /// Determine if this callee function can be specialized or not.
 bool ExistentialSpecializer::canSpecializeCalleeFunction(FullApplySite &Apply) {
-
   /// Determine the caller of the apply.
   auto *Callee = Apply.getReferencedFunctionOrNull();
   if (!Callee)
@@ -221,6 +220,13 @@ bool ExistentialSpecializer::canSpecializeCalleeFunction(FullApplySite &Apply) {
   if (!Callee->isDefinition())
     return false;
 
+  // If the callee has ownership enabled, bail.
+  //
+  // FIXME: We should be able to handle callees that have ownership, but the
+  // pass has not been updated yet.
+  if (Callee->hasOwnership())
+    return false;
+
   /// Ignore functions with indirect results.
   if (Callee->getConventions().hasIndirectSILResults())
     return false;