Regressions on master at commit r15-8963 vs commit r15-8948 on Linux/x86_64

[Haochen Jiang]

Regressions on master at commit r15-8963 vs commit r15-8948 on Linux/x86_64
New failures:
FAIL: g++.dg/strub-internal-pr112938.C  -std=gnu++26 (test for excess errors)
FAIL: g++.dg/strub-internal-pr112938.C  -std=gnu++26 (test for excess errors)
FAIL: g++.dg/template/explicit-args6.C  -std=c++11  (test for warnings, line 23)
FAIL: g++.dg/template/explicit-args6.C  -std=c++11  (test for warnings, line 23)
FAIL: g++.dg/template/explicit-args6.C  -std=c++17  (test for warnings, line 23)
FAIL: g++.dg/template/explicit-args6.C  -std=c++17  (test for warnings, line 23)
FAIL: g++.dg/template/explicit-args6.C  -std=c++26  (test for warnings, line 23)
FAIL: g++.dg/template/explicit-args6.C  -std=c++26  (test for warnings, line 23)

New passes: