[gcc r16-956] libstdc++: Fix another 17_intro/names.cc failure on AIX

[Jonathan Wakely]

https://gcc.gnu.org/g:8e7cf04d54f5ffb540fdd5406010bb162b9f472b

commit r16-956-g8e7cf04d54f5ffb540fdd5406010bb162b9f472b
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue May 27 21:50:24 2025 +0100

    libstdc++: Fix another 17_intro/names.cc failure on AIX
    
    FAIL: 17_intro/names.cc  -std=gnu++98 (test for excess errors)
    
    Also fix typo in experimental/names.cc where I did #undef for the wrong
    name in r16-901-gd1ced2a5ea6b09.
    
    libstdc++-v3/ChangeLog:
    
            * testsuite/17_intro/names.cc [_AIX] (a): Undefine.
            * testsuite/experimental/names.cc [_AIX] (ptr): Undefine.

Diff:
---
 libstdc++-v3/testsuite/17_intro/names.cc     | 2 ++
 libstdc++-v3/testsuite/experimental/names.cc | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/testsuite/17_intro/names.cc b/libstdc++-v3/testsuite/17_intro/names.cc
index a61e49dc8191..f32205d9c7f5 100644
--- a/libstdc++-v3/testsuite/17_intro/names.cc
+++ b/libstdc++-v3/testsuite/17_intro/names.cc
@@ -248,6 +248,8 @@
 #undef r
 #undef x
 #undef y
+// <stdlib.h> defines drand48_data::a
+#undef a
 // <sys/localedef.h> defines _LC_weight_t::n
 #undef n
 // <sys/poll.h> defines pollfd_ext::u on AIX 7.3
diff --git a/libstdc++-v3/testsuite/experimental/names.cc b/libstdc++-v3/testsuite/experimental/names.cc
index 4bedd530ecc5..94ae76fc610b 100644
--- a/libstdc++-v3/testsuite/experimental/names.cc
+++ b/libstdc++-v3/testsuite/experimental/names.cc
@@ -25,7 +25,7 @@
 
 #ifdef _AIX
 // <netdb.h> declares endnetgrent_r with ptr parameter.
-# undef n
+# undef ptr
 #endif
 
 // Filesystem