Regressions on trunk at revision 216513 vs revision 216482

[H.J. Lu x32]

New failures:
FAIL: g++.dg/ipa/devirt-42.C  -std=gnu++11  scan-tree-dump-times optimized "return 2" 2
FAIL: g++.dg/ipa/devirt-42.C  -std=gnu++1y  scan-tree-dump-times optimized "return 2" 2
FAIL: g++.dg/ipa/devirt-42.C  -std=gnu++98  scan-tree-dump-times optimized "return 2" 2

New passes:
FAIL: gcc.dg/guality/pr54693-2.c   -Os  line 21 x == 10 - i
FAIL: gcc.dg/guality/pr54693-2.c   -Os  line 21 y == 20 - 2 * i
FAIL: gcc.target/i386/avx512f-vec-unpack.c (internal compiler error)
FAIL: gcc.target/i386/avx512f-vec-unpack.c (test for excess errors)