Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
PrettyDeclStackTraceEntry - If a crash occurs in the parser while parsing something related to a decl...
PrettyDeclStackTraceEntry(ASTContext &Ctx, Decl *D, SourceLocation Loc, const char *Msg)
void print(raw_ostream &OS) const override