[gcc r16-3729] testsuite: Fix UNRESOLVEDs for mistakenly dg-run test [PR121872]

[Nathaniel Shead]

https://gcc.gnu.org/g:86e470b25989df189311295819976873058ead65

commit r16-3729-g86e470b25989df189311295819976873058ead65
Author: Nathaniel Shead <nathanieloshead@gmail.com>
Date:   Tue Sep 9 22:55:35 2025 +1000

    testsuite: Fix UNRESOLVEDs for mistakenly dg-run test [PR121872]
    
            PR testsuite/121872
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/modules/default-arg-4_b.C: Change run to compile.
    
    Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>

Diff:
---
 gcc/testsuite/g++.dg/modules/default-arg-4_b.C | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/testsuite/g++.dg/modules/default-arg-4_b.C b/gcc/testsuite/g++.dg/modules/default-arg-4_b.C
index 7ed003ff3982..5800ea208072 100644
--- a/gcc/testsuite/g++.dg/modules/default-arg-4_b.C
+++ b/gcc/testsuite/g++.dg/modules/default-arg-4_b.C
@@ -1,5 +1,6 @@
 // C++20 P1766R1 - Mitigating minor modules maladies
-// { dg-module-do run }
+// FIXME mark as run once we no longer xfail below.
+// { dg-module-do compile }
 // { dg-additional-options "-fmodules-ts" }
 
 import M;