LibJS: Only check for duplicate exports if they have a name

Together with removing an incorrect VERIFY this allows multiple star
imports in a single module.

Userland/Libraries/LibJS/AST.cpp

@@ -4498,7 +4498,7 @@ 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)
+        if (entry.kind != ExportEntry::Kind::NamedExport)
             return false;
         return entry.export_name == export_name;
     });

Userland/Libraries/LibJS/SourceTextModule.cpp

@@ -202,8 +202,6 @@ Result<NonnullRefPtr<SourceTextModule>, Vector<Parser::Error>> SourceTextModule:
                     // 2. If ie.[[ImportName]] is namespace-object, then
                     if (import_entry.is_namespace) {
                         // a. NOTE: This is a re-export of an imported module namespace object.
-                        VERIFY(export_entry.is_module_request() && export_entry.kind != ExportStatement::ExportEntry::Kind::NamedExport);
-
                         // b. Append ee to localExportEntries.
                         local_export_entries.empend(export_entry);
                     }

Userland/Libraries/LibJS/Tests/modules/basic-modules.js

@@ -186,6 +186,10 @@ describe("in- and exports", () => {
     test("namespace has expected ordering", () => {
         expectModulePassed("./namespace-order.mjs");
     });
+
+    test("can have multiple star imports even from the same file", () => {
+        expectModulePassed("./multiple-star-imports.mjs");
+    });
 });
 
 describe("loops", () => {

Userland/Libraries/LibJS/Tests/modules/multiple-star-imports.mjs

@@ -0,0 +1,4 @@
+import * as ns1 from "./default-and-star-export.mjs";
+import * as ns2 from "./default-and-star-export.mjs";
+
+export const passed = ns1 === ns2;