AST: Static properties of fixed-layout types are resilient

We don't want @_fixed_layout to apply to static properties, or you
get fun consequences like not being able to change static stored
properties defined in extensions of imported types to computed.

lib/Sema/CodeSynthesis.cpp

@@ -276,9 +276,8 @@ static void maybeMarkTransparent(FuncDecl *accessor,
   if (!nominalDecl)
     return;
 
-  // Accessors for stored properties of resilient types are not
-  // @_transparent.
-  if (nominalDecl->isResilient())
+  // Accessors for resilient properties are not @_transparent.
+  if (storage->isResilient())
     return;
 
   // Accessors for protocol storage requirements are never @_transparent