Add annotation information

[landaire]

Suggestion from this tweet: https://twitter.com/sixtyvividtails/status/1370443148615430150

It's possible, but I sort of footgunned myself by not recording SymbolIndex information. It may be an implementation detail that compilers write annotation info first which would allow for adding them to some list, then when we parse the symbol the attribute is for (AnnotationReferenceSymbol::symbol_index), check if there are any attributes for that symbol.