[gcc r13-4801] build: avoid -Wconditionally-supported on qsort check

[gcc r13-4801] build: avoid -Wconditionally-supported on qsort check

[Jason Merrill]

https://gcc.gnu.org/g:1e007fa5c92ae2d6b64854a6faad7e85b43d64f2

commit r13-4801-g1e007fa5c92ae2d6b64854a6faad7e85b43d64f2
Author: Jason Merrill <jason@redhat.com>
Date:   Mon Dec 19 15:41:36 2022 -0500

    build: avoid -Wconditionally-supported on qsort check
    
    It's OK to rely on conditionally-supported features in #if CHECKING_P, since
    that isn't defined in stage 1.
    
    gcc/ChangeLog:
    
            * sort.cc: Disable -Wconditionally-supported in
            CHECKING_P code.

Diff:
---
 gcc/sort.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/gcc/sort.cc b/gcc/sort.cc
index 87f826818bb..eeddfcf1fef 100644
--- a/gcc/sort.cc
+++ b/gcc/sort.cc
@@ -237,6 +237,10 @@ do {                                            \
 }
 
 #if CHECKING_P
+  /* Don't complain about cast from void* to function pointer.  */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wconditionally-supported"
+
 /* Adapter for using two-argument comparators in functions expecting the
    three-argument sort_r_cmp_fn type.  */
 static int
@@ -266,6 +270,7 @@ gcc_qsort (void *vbase, size_t n, size_t size, cmp_fn *cmp)
     free (buf);
 #if CHECKING_P
   qsort_chk (vbase, n, size, cmp2to3, (void*)cmp);
+#pragma GCC diagnostic pop
 #endif
 }