Regressions on native/releases/gcc-15 at commit r15-10597 vs commit r15-10596 on Linux/x86_64

[Haochen Jiang via Gcc-regression]

Regressions on releases/gcc-15 at commit r15-10597 vs commit r15-10596 on 
Linux/x86_64
New failures:

New passes:
FAIL: 27_io/basic_istream/ignore/char/94749.cc  -std=gnu++17 execution test