[committed] libstdc++: Make names_pstl.cc require et tbb_backend

[Jonathan Wakely <jwakely@redhat.com>]

Sigh ... this test still isn't right, because it fails on systems
without a bug-fix for TBB 2020.3. We could just add -fpermissive to the
test options, but let's just require tbb_backend (which isn't matched on
systems with the buggy headers). Separately, I'm going to backport the
TBB fix to Fedora 37 where I had the test FAIL.

Tested x86_64-linux (Fedora 37 this time). Pushed to trunk.

-- >8 --

The https://github.com/oneapi-src/oneTBB/pull/833 fix is needed for TBB
headers to avoid an error with GCC 13. The new names_pstl.cc test needs
to check effective target tbb_backend so that it's UNSUPPORTED on
systems without fixed headers.

libstdc++-v3/ChangeLog:

	* testsuite/17_intro/names_pstl.cc: Require et tbb_backend.
---
 libstdc++-v3/testsuite/17_intro/names_pstl.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/testsuite/17_intro/names_pstl.cc b/libstdc++-v3/testsuite/17_intro/names_pstl.cc
index 42ce098550c..019e4774ff2 100644
--- a/libstdc++-v3/testsuite/17_intro/names_pstl.cc
+++ b/libstdc++-v3/testsuite/17_intro/names_pstl.cc
@@ -1,10 +1,12 @@
 // { dg-do compile { target c++17 } }
-// { dg-additional-options "-DTBB_SUPPRESS_DEPRECATED_MESSAGES=1" { target tbb_backend } }
+// { dg-require-effective-target tbb_backend }
+// { dg-add-options no_pch }
 
 // The TBB headers use non-reserved names (because they're not part of the
 // implementation) so we need to include them before the macro definitions
 // in names.cc:
 #if __has_include(<tbb/tbb.h>)
+# define TBB_SUPPRESS_DEPRECATED_MESSAGES 1
 # include <tbb/tbb.h>
 #endif
 // Now we can define the macros to poison uses of non-reserved names:
-- 
2.39.1