Regressions on trunk at revision 255795 vs revision 255776

[H.J. Lu ia32 Core i7]

New failures:

New passes:
FAIL: g++.dg/pr79095-4.C  -std=gnu++11  scan-tree-dump-times vrp2 "__builtin_memset \\(_[0-9]+, 0, [0-9]+\\)" 1 (found 0 times)
FAIL: g++.dg/pr79095-4.C  -std=gnu++11  (test for warnings, line )
FAIL: g++.dg/pr79095-4.C  -std=gnu++14  scan-tree-dump-times vrp2 "__builtin_memset \\(_[0-9]+, 0, [0-9]+\\)" 1 (found 0 times)
FAIL: g++.dg/pr79095-4.C  -std=gnu++14  (test for warnings, line )
FAIL: g++.dg/pr79095-4.C  -std=gnu++98  scan-tree-dump-times vrp2 "__builtin_memset \\(_[0-9]+, 0, [0-9]+\\)" 1 (found 0 times)
FAIL: g++.dg/pr79095-4.C  -std=gnu++98  (test for warnings, line )