Regressions on master at commit r16-7363 vs commit r16-7357 on Linux/x86_64

[Haochen Jiang]

Regressions on master at commit r16-7363 vs commit r16-7357 on Linux/x86_64
New failures:
FAIL: gcc.dg/lto/save-temps c_lto_save-temps_0.o-c_lto_save-temps_0.o link,  -O -flto -save-temps

New passes:
FAIL: gcc.dg/lto/pr122515, ar returned 1: /export/home/haochenj/src/gcc-regression/bld/gcc/gcc-ar: Cannot find plugin 'liblto_plugin.so'
FAIL: gcc.dg/lto/pr122515, ar returned 1: /export/home/haochenj/src/gcc-regression/bld/gcc/gcc-ar: Cannot find plugin 'liblto_plugin.so'
FAIL: gcc.target/i386/pr109362.c scan-assembler \tmovq\t8\\(%rdi\\), %r
FAIL: g++.dg/concepts/expression.C  -std=gnu++17 (test for excess errors)
FAIL: g++.dg/concepts/expression.C  -std=gnu++17 (test for excess errors)