[libstdc++] [testsuite] intro/names.cc: undef func on vxw7krn

[Alexandre Oliva <oliva@adacore.com>]

The '#define func' added in 2021, to test that system headers don't
violate the user namespace, exposes such a bug in the vxworks sysLib.h
header, so add yet another such annotated workaround.

Regstrapped on x86_64-linux-gnu.
Tested on arm-vxworks7 (gcc-12) and arm-eabi (trunk).  Ok to install?

for  libstdc++-v3/ChangeLog

	* testsuite/17_intro/names.cc: Undef func on vxworks >= 7 in
	kernel mode.
---
 libstdc++-v3/testsuite/17_intro/names.cc |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/libstdc++-v3/testsuite/17_intro/names.cc b/libstdc++-v3/testsuite/17_intro/names.cc
index d3e0db9bab6b9..c2d67ebe01276 100644
--- a/libstdc++-v3/testsuite/17_intro/names.cc
+++ b/libstdc++-v3/testsuite/17_intro/names.cc
@@ -329,6 +329,8 @@
 #undef d
 #undef e
 #undef f
+// in sysLib.h, func appears as a formal parameter name
+#undef func
 #endif // __RTP__
 
 #endif // VxWorks Major >= 7

-- 
Alexandre Oliva, happy hacker                https://FSFLA.org/blogs/lxo/
   Free Software Activist                       GNU Toolchain Engineer
Disinformation flourishes because many people care deeply about injustice
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