fix(test): a generic function called from a test block works

Test blocks were never type-checked, and the checker is what makes a
generic call real; they are checked like entry now. Reseed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

selfhost/check/check_stmt.ludic

@@ -185,6 +185,12 @@ function check_program() -> void {
     ck_listener(g_onlisten[j])
     j += 1
   }
+  # a test block is checked like `entry`: that is also what makes its generic calls real
+  j = 0
+  while j < len(g_tests) {
+    ck_block(g_tests[j].a)
+    j += 1
+  }
   gen_finish()
   if ck_errors > 0 and not ck_reporting() {
     let m = `{itoa(ck_errors)} type error(s)\n`