[gcc r13-1151] libstdc++: Add missing #include <string> to new test

[gcc r13-1151] libstdc++: Add missing #include <string> to new test

[Jonathan Wakely]

https://gcc.gnu.org/g:0f96ac43fa0a5fdbfce317b274233852d5b46d23

commit r13-1151-g0f96ac43fa0a5fdbfce317b274233852d5b46d23
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Jun 17 13:29:05 2022 +0100

    libstdc++: Add missing #include <string> to new test
    
    Somehow I pushed a different version of this test to the one I actually
    tested.
    
    libstdc++-v3/ChangeLog:
    
            * testsuite/21_strings/basic_string/cons/char/105995.cc: Add
            missing #include.

Diff:
---
 libstdc++-v3/testsuite/21_strings/basic_string/cons/char/105995.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/105995.cc b/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/105995.cc
index aa8bcba3dca..4764ceff72a 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/105995.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/105995.cc
@@ -2,6 +2,8 @@
 // { dg-do compile { target c++20 } }
 // { dg-require-effective-target cxx11_abi }
 
+#include <string>
+
 // PR libstdc++/105995
 // Not required by the standard, but supported for QoI.
 constexpr std::string pr105995_empty;