LibJS: Handle empty named export

This is an export which looks like `export {} from "module"`, and
although it doesn't have any real export entries it should still add
"module" to the required modules to load.

Userland/Libraries/LibJS/AST.cpp

@@ -4497,6 +4497,9 @@ void ImportStatement::dump(int indent) const
 bool ExportStatement::has_export(FlyString const& export_name) const
 {
     return any_of(m_entries.begin(), m_entries.end(), [&](auto& entry) {
+        // Make sure that empty exported names does not overlap with anything
+        if (entry.kind == ExportEntry::Kind::EmptyNamedExport)
+            return false;
         return entry.export_name == export_name;
     });
 }