Regressions on trunk at revision 255758 vs revision 255750

[H.J. Lu Intel64 Core i7]

New failures:
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  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++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  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++14  (test for warnings, line )

New passes: