Regressions on native/master at commit r15-5950 vs commit r15-5940 on Linux/x86_64

[Haochen Jiang]

Regressions on master at commit r15-5950 vs commit r15-5940 on Linux/x86_64
New failures:

New passes:
FAIL: gcc.dg/guality/pr58791-4.c   -Os  -DPREVENT_OPTIMIZATION  line pr58791-4.c:32 i2 == 487
FAIL: gcc.dg/guality/pr58791-4.c   -Os  -DPREVENT_OPTIMIZATION  line pr58791-4.c:32 i == 486
FAIL: gfortran.dg/sizeof_6.f90   -O1  execution test