always print enum elements

in some situations, enum element decls are being skipped when rendering
declaration fragments. this trips an assertion in the declaration
fragment renderer that ensures that it always renders something. by
always rendering enum elements, we can sidestep this issue.

Author: QuietMisdreavus

lib/SymbolGraphGen/SymbolGraph.cpp

@@ -72,7 +72,7 @@ PrintOptions SymbolGraph::getDeclarationFragmentsPrintOptions() const {
   Opts.SkipUnderscoredStdlibProtocols = true;
   Opts.PrintGenericRequirements = true;
   Opts.PrintInherited = false;
-  Opts.ExplodeEnumCaseDecls = IsForSingleNode;
+  Opts.ExplodeEnumCaseDecls = true;
 
   Opts.ExclusiveAttrList.clear();