LibPDF: Avoid unnecessary HashMap copy, mark other copies

Userland/Libraries/LibPDF/Encoding.cpp

@@ -43,8 +43,8 @@ PDFErrorOr<NonnullRefPtr<Encoding>> Encoding::from_object(Document* document, No
 
     auto encoding = adopt_ref(*new Encoding());
 
-    encoding->m_descriptors = base_encoding->m_descriptors;
-    encoding->m_name_mapping = base_encoding->m_name_mapping;
+    encoding->m_descriptors = TRY(base_encoding->m_descriptors.clone());
+    encoding->m_name_mapping = TRY(base_encoding->m_name_mapping.clone());
 
     auto differences_array = TRY(dict->get_array(document, CommonNames::Differences));
 

Userland/Libraries/LibPDF/Parser.cpp

@@ -432,7 +432,7 @@ PDFErrorOr<NonnullRefPtr<DictObject>> Parser::parse_dict()
         return error("Expected dict to end with \">>\"");
     m_reader.consume_whitespace();
 
-    return make_object<DictObject>(map);
+    return make_object<DictObject>(move(map));
 }
 
 PDFErrorOr<NonnullRefPtr<StreamObject>> Parser::parse_stream(NonnullRefPtr<DictObject> dict)