Don't emit the property wrapper backing initializer publicly for resilient properties

Author: DougGregor

lib/SIL/SILDeclRef.cpp

@@ -313,6 +313,13 @@ SILLinkage SILDeclRef::getLinkage(ForDefinition_t forDefinition) const {
     limit = Limit::NeverPublic;
   }
 
+  // The property wrapper backing initializer is never public for resilient
+  // properties.
+  if (kind == SILDeclRef::Kind::PropertyWrapperBackingInitializer) {
+    if (cast<VarDecl>(d)->isResilient())
+      limit = Limit::NeverPublic;
+  }
+
   // Stored property initializers get the linkage of their containing type.
   if (isStoredPropertyInitializer()) {
     // Three cases: