Regressions on native/releases/gcc-15 at commit r15-10789 vs commit r15-10787 on Linux/x86_64

[Haochen Jiang]

Regressions on releases/gcc-15 at commit r15-10789 vs commit r15-10787 on Linux/x86_64
New failures:
FAIL: gcc.dg/lto/pr122515, ar returned 1: /home/haochenj/src/gcc-15-regression/bld/gcc/gcc-ar: Cannot find plugin 'liblto_plugin.so'
FAIL: gcc.dg/lto/pr122515, ar returned 1: /home/haochenj/src/gcc-15-regression/bld/gcc/gcc-ar: Cannot find plugin 'liblto_plugin.so'

New passes: