Regressions on native/master at commit r15-1735 vs commit r15-1730 on Linux/x86_64

[Haochen Jiang]

Regressions on master at commit r15-1735 vs commit r15-1730 on Linux/x86_64
New failures:
FAIL: gcc.dg/guality/vla-1.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  -DPREVENT_OPTIMIZATION line 17 sizeof (a) == 6
FAIL: gcc.dg/guality/vla-1.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  -DPREVENT_OPTIMIZATION line 17 sizeof (a) == 6
FAIL: gcc.dg/guality/vla-1.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  -DPREVENT_OPTIMIZATION line 24 sizeof (a) == 17 * sizeof (short)

New passes:
FAIL: gcc.dg/guality/vla-1.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  -DPREVENT_OPTIMIZATION line 24 i == 5
FAIL: gcc.dg/pr10474.c scan-rtl-dump pro_and_epilogue "Performing shrink-wrapping"
FAIL: gcc.target/i386/pr91333.c scan-assembler-times vmovapd|vmovsd 3
FAIL: gcc.target/i386/vect-strided-3.c scan-assembler-times movq 4