[gcc r13-8238] libstdc++: Fix std::format test for Solaris [PR113450]

[Jonathan Wakely]

https://gcc.gnu.org/g:5240df78a07303a37b1f0b83165624d2a648089e

commit r13-8238-g5240df78a07303a37b1f0b83165624d2a648089e
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Wed Jan 17 21:40:25 2024 +0000

    libstdc++: Fix std::format test for Solaris [PR113450]
    
    When int8_t is a typedef for char (rather than signed char) this test
    fails because it tries to format a char, which is treated differently
    from formatting other integral types (including signed char).
    
    Use signed char explicitly so the result doesn't depend on the
    non-portable definition of int8_t.
    
    libstdc++-v3/ChangeLog:
    
            PR libstdc++/113450
            * testsuite/std/format/functions/format.cc: Use signed char
            instead of int8_t.
    
    (cherry picked from commit db42a0a98916340af33338c08e6a7d328121b958)

Diff:
---
 libstdc++-v3/testsuite/std/format/functions/format.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/testsuite/std/format/functions/format.cc b/libstdc++-v3/testsuite/std/format/functions/format.cc
index e9827d0b735..6c32100d0f8 100644
--- a/libstdc++-v3/testsuite/std/format/functions/format.cc
+++ b/libstdc++-v3/testsuite/std/format/functions/format.cc
@@ -351,7 +351,7 @@ test_minmax()
     s = std::format("{:b}" , std::numeric_limits<U>::max());
     VERIFY( s == '1' + ones );
   };
-  check(std::int8_t(0));
+  check((signed char)(0)); // int8_t is char on Solaris, see PR 113450
   check(std::int16_t(0));
   check(std::int32_t(0));
   check(std::int64_t(0));