libstdc++: Remove dg-options "-std=gnu++20" from 27_io tests

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/27_io/basic_istream/extractors_character/char/lwg2499.cc:
	Remove dg-options -std=gnu++2a.
	* testsuite/27_io/basic_istream/extractors_character/char/lwg2499_neg.cc:
	Likewise.
	* testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499.cc:
	Likewise.
	* testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499_neg.cc:
	Likewise.
	* testsuite/27_io/basic_istringstream/cons/char/1.cc: Likewise.
	* testsuite/27_io/basic_istringstream/cons/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_istringstream/str/char/2.cc: Likewise.
	* testsuite/27_io/basic_istringstream/str/wchar_t/2.cc:
	Likewise.
	* testsuite/27_io/basic_istringstream/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_istringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_ostream/emit/1.cc: Likewise.
	* testsuite/27_io/basic_ostream/inserters_character/char/deleted.cc:
	Likewise.
	* testsuite/27_io/basic_ostream/inserters_character/wchar_t/deleted.cc:
	Likewise.
	* testsuite/27_io/basic_ostringstream/cons/char/1.cc: Likewise.
	* testsuite/27_io/basic_ostringstream/cons/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_ostringstream/str/char/3.cc: Likewise.
	* testsuite/27_io/basic_ostringstream/str/wchar_t/3.cc:
	Likewise.
	* testsuite/27_io/basic_ostringstream/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_ostringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_stringbuf/cons/char/2.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/cons/wchar_t/2.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/str/char/4.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/str/wchar_t/4.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/view/wchar_t/1.cc: Likewise.
	* testsuite/27_io/basic_stringstream/cons/char/1.cc: Likewise.
	* testsuite/27_io/basic_stringstream/cons/char/97719.cc:
	Likewise.
	* testsuite/27_io/basic_stringstream/cons/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_stringstream/str/char/5.cc: Likewise.
	* testsuite/27_io/basic_stringstream/str/wchar_t/5.cc.cc:
	Likewise.
	* testsuite/27_io/basic_stringstream/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_stringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_syncbuf/1.cc: Likewise.
	* testsuite/27_io/basic_syncbuf/2.cc: Likewise.
	* testsuite/27_io/basic_syncbuf/basic_ops/1.cc: Likewise.
	* testsuite/27_io/basic_syncbuf/requirements/types.cc: Likewise.
	* testsuite/27_io/basic_syncbuf/sync_ops/1.cc: Likewise.
	* testsuite/27_io/basic_syncstream/1.cc: Likewise.
	* testsuite/27_io/basic_syncstream/2.cc: Likewise.
	* testsuite/27_io/basic_syncstream/basic_ops/1.cc: Likewise.
	* testsuite/27_io/basic_syncstream/requirements/types.cc:
	Likewise.
	* testsuite/27_io/filesystem/iterators/106201.cc: Likewise.
	* testsuite/27_io/filesystem/iterators/lwg3719.cc: Likewise.
	* testsuite/27_io/filesystem/path/factory/u8path-depr.cc:
	Likewise.
	* testsuite/27_io/filesystem/path/nonmember/cmp_c++20.cc:
	Likewise.

4 files changed, 4 insertions, 8 deletions

diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/char/lwg2499.cc b/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/char/lwg2499.cc
index 75ec75b..060cb93 100644
--- a/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/char/lwg2499.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/char/lwg2499.cc
@@ -15,8 +15,7 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-options "-std=gnu++2a" }
-// { dg-do run { target c++2a } }
+// { dg-do run { target c++20 } }
 
 // LWG 2499
 // operator>>(basic_istream&, CharT*) makes it hard to avoid buffer overflows
diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/char/lwg2499_neg.cc b/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/char/lwg2499_neg.cc
index a214365..02b0e9a 100644
--- a/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/char/lwg2499_neg.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/char/lwg2499_neg.cc
@@ -15,8 +15,7 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-options "-std=gnu++2a" }
-// { dg-do compile { target c++2a } }
+// { dg-do compile { target c++20 } }
 
 // LWG 2499
 // operator>>(basic_istream&, CharT*) makes it hard to avoid buffer overflows
diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499.cc b/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499.cc
index 62689b3..9605a4f 100644
--- a/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499.cc
@@ -15,8 +15,7 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-options "-std=gnu++2a" }
-// { dg-do run { target c++2a } }
+// { dg-do run { target c++20 } }
 
 // LWG 2499
 // operator>>(basic_istream&, CharT*) makes it hard to avoid buffer overflows
diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499_neg.cc b/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499_neg.cc
index dae4935..3e808aa 100644
--- a/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499_neg.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499_neg.cc
@@ -15,8 +15,7 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-options "-std=gnu++2a" }
-// { dg-do compile { target c++2a } }
+// { dg-do compile { target c++20 } }
 
 // LWG 2499
 // operator>>(basic_istream&, CharT*) makes it hard to avoid buffer overflows