[gcc r15-3522] c++: adjust testcase to reveal failure [PR107919]

[Jason Merrill via Gcc-cvs]

https://gcc.gnu.org/g:1fa45e77154732af147e87aee1779a3b10db2b7a

commit r15-3522-g1fa45e77154732af147e87aee1779a3b10db2b7a
Author: Jason Merrill <ja...@redhat.com>
Date:   Fri Sep 6 15:14:33 2024 -0400

    c++: adjust testcase to reveal failure [PR107919]
    
    This test appeared to be passing, but only because the warning was
    suppressed by #pragma system_header.
    
            PR tree-optimization/107919
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/warn/Wuninitialized-pr107919-1.C: Add -Wsystem-headers and
            xfail.

Diff:
---
 gcc/testsuite/g++.dg/warn/Wuninitialized-pr107919-1.C | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/gcc/testsuite/g++.dg/warn/Wuninitialized-pr107919-1.C 
b/gcc/testsuite/g++.dg/warn/Wuninitialized-pr107919-1.C
index 067a44a462e..049fa4d307a 100644
--- a/gcc/testsuite/g++.dg/warn/Wuninitialized-pr107919-1.C
+++ b/gcc/testsuite/g++.dg/warn/Wuninitialized-pr107919-1.C
@@ -1,6 +1,6 @@
 // { dg-do compile }
 // { dg-require-effective-target c++17 }
-// { dg-options "-O2 -Wuninitialized" }
+// { dg-options "-O2 -Wuninitialized -Wsystem-headers" }
 
 #include <memory>
 #include <variant>
@@ -13,3 +13,5 @@ void do_something(void* storage)
   auto& swappedValue = *reinterpret_cast<Event*>(storage);
   std::swap(event, swappedValue);
 }
+
+// { dg-bogus "may be used uninitialized" "" { xfail *-*-* } 0 }