[committed] libstdc++: Disable test on targets without mkfifo [PR118158]

[Jonathan Wakely]

This test fails to compile using mingw-w64 so disable it using the
dg-require-mkfifo directive.

libstdc++-v3/ChangeLog:

	PR libstdc++/118158
	* testsuite/27_io/filesystem/operations/pr118158.cc: Add
	dg-require-mkfifo.
---

Tested x86_64-linux. Pushed to trunk. Needed on gcc-15 and gcc-16 too.

 libstdc++-v3/testsuite/27_io/filesystem/operations/pr118158.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libstdc++-v3/testsuite/27_io/filesystem/operations/pr118158.cc b/libstdc++-v3/testsuite/27_io/filesystem/operations/pr118158.cc
index b57a2d184f41..43b8442bd203 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/operations/pr118158.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/operations/pr118158.cc
@@ -1,5 +1,6 @@
 // { dg-do run { target c++17 } }
 // { dg-require-filesystem-ts "" }
+// { dg-require-mkfifo "" }
 
 #include <filesystem>
 #include <testsuite_fs.h>
-- 
2.54.0