test(ffi-linkage): xfail postfix extern on #objc_class aggregate (Phase 3.0)

examples/1348-ffi-objc-extern-class.sx

@@ -0,0 +1,28 @@
+// Phase 3.0 (FFI-linkage) — postfix `extern` on an aggregate (`#objc_class`)
+// is the new spelling of the legacy prefix `#foreign #objc_class` import.
+// Mirrors 1306's foreign-class chained dispatch with the new syntax:
+//   Name :: #objc_class("X") extern { … }   ==   Name :: #foreign #objc_class("X") { … }
+//
+// Red until 3.1 wires the postfix-extern aggregate path through the parser
+// + lowering (maps `extern` → reference, same as `#foreign`).
+
+#import "modules/std.sx";
+#import "modules/build.sx";
+
+NSObject :: #objc_class("NSObject") extern {
+    alloc :: () -> *NSObject;
+    init :: (self: *Self) -> *Self;
+}
+
+main :: () -> i32 {
+    inline if OS == .macos {
+        a := NSObject.alloc().init();
+        if a != null {
+            print("extern-class dispatch ok\n");
+        }
+    }
+    inline if OS != .macos {
+        print("extern-class dispatch ok\n");
+    }
+    0
+}

examples/expected/1348-ffi-objc-extern-class.exit

@@ -0,0 +1 @@
+0

examples/expected/1348-ffi-objc-extern-class.stdout

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+extern-class dispatch ok