Regressions on master at commit r16-3671 vs commit r16-3670 on Linux/x86_64

[Haochen Jiang]

Regressions on master at commit r16-3671 vs commit r16-3670 on Linux/x86_64
New failures:

New passes:
FAIL: 27_io/basic_ostream/emit/1.cc  -std=gnu++20 (test for excess errors)
FAIL: 27_io/basic_ostream/emit/1.cc  -std=gnu++20 (test for excess errors)
FAIL: 27_io/basic_ostream/emit/1.cc  -std=gnu++26 (test for excess errors)
FAIL: 27_io/basic_ostream/emit/1.cc  -std=gnu++26 (test for excess errors)
FAIL: 27_io/basic_syncbuf/basic_ops/1.cc  -std=gnu++20 (test for excess errors)
FAIL: 27_io/basic_syncbuf/basic_ops/1.cc  -std=gnu++20 (test for excess errors)
FAIL: 27_io/basic_syncbuf/basic_ops/1.cc  -std=gnu++26 (test for excess errors)
FAIL: 27_io/basic_syncbuf/basic_ops/1.cc  -std=gnu++26 (test for excess errors)
FAIL: 27_io/basic_syncbuf/sync_ops/1.cc  -std=gnu++20 (test for excess errors)
FAIL: 27_io/basic_syncbuf/sync_ops/1.cc  -std=gnu++20 (test for excess errors)
FAIL: 27_io/basic_syncbuf/sync_ops/1.cc  -std=gnu++26 (test for excess errors)
FAIL: 27_io/basic_syncbuf/sync_ops/1.cc  -std=gnu++26 (test for excess errors)
FAIL: 27_io/basic_syncstream/basic_ops/1.cc  -std=gnu++20 (test for excess errors)
FAIL: 27_io/basic_syncstream/basic_ops/1.cc  -std=gnu++20 (test for excess errors)
FAIL: 27_io/basic_syncstream/basic_ops/1.cc  -std=gnu++26 (test for excess errors)
FAIL: 27_io/basic_syncstream/basic_ops/1.cc  -std=gnu++26 (test for excess errors)