[glibc] Fix stdlib/tst-setcontext.c for GCC 12 -Warray-compare

[Joseph Myers]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=a0f0c08e4fe18e78866539b0571f8e4b57dba7a3

commit a0f0c08e4fe18e78866539b0571f8e4b57dba7a3
Author: Joseph Myers <joseph@codesourcery.com>
Date:   Tue Oct 5 14:25:40 2021 +0000

    Fix stdlib/tst-setcontext.c for GCC 12 -Warray-compare
    
    Building stdlib/tst-setcontext.c fails with GCC mainline:
    
    tst-setcontext.c: In function 'f2':
    tst-setcontext.c:61:16: error: comparison between two arrays [-Werror=array-compare]
       61 |   if (on_stack < st2 || on_stack >= st2 + sizeof (st2))
          |                ^
    tst-setcontext.c:61:16: note: use '&on_stack[0] < &st2[0]' to compare the addresses
    
    The comparison in this case is deliberate, so adjust it as suggested
    in that note.
    
    Tested with build-many-glibcs.py (GCC mainline) for aarch64-linux-gnu.

Diff:
---
 stdlib/tst-setcontext.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/stdlib/tst-setcontext.c b/stdlib/tst-setcontext.c
index 1b511708c1..1c2925bb76 100644
--- a/stdlib/tst-setcontext.c
+++ b/stdlib/tst-setcontext.c
@@ -58,7 +58,7 @@ f2 (void)
   puts ("start f2");
 
   printf ("&on_stack=%p\n", on_stack);
-  if (on_stack < st2 || on_stack >= st2 + sizeof (st2))
+  if (&on_stack[0] < &st2[0] || &on_stack[0] >= st2 + sizeof (st2))
     {
       printf ("%s: memory stack is not where it belongs!", __FUNCTION__);
       exit (1);