Regressions on trunk at revision 274538 vs revision 274495

[H.J. Lu (Intel64 Core i7)]

New failures:
FAIL: gcc.dg/tree-ssa/pr64910-2.c scan-assembler-times and|test 20

New passes:
FAIL: gcc.target/i386/pr65105-3.c scan-assembler ptest
FAIL: gcc.target/i386/pr65105-5.c scan-assembler ptest
FAIL: gcc.target/i386/pr78794.c scan-assembler pandn