Regressions on trunk at revision 255202 vs revision 255188

[H.J. Lu Intel64 Core i7]

New failures:
FAIL: c-c++-common/ubsan/unreachable-2.c   -O2  execution test
FAIL: c-c++-common/ubsan/unreachable-2.c   -O2  execution test
FAIL: c-c++-common/ubsan/unreachable-2.c   -O2  execution test
FAIL: c-c++-common/ubsan/unreachable-2.c   -O2  execution test

New passes:
FAIL: gcc.target/i386/pr78057.c scan-tree-dump-not optimized "__builtin_ia32_[lt]zcnt"
FAIL: gcc.target/i386/pr78057.c scan-tree-dump-times optimized "__builtin_clz " 1 (found 0 times)
FAIL: gcc.target/i386/pr78057.c scan-tree-dump-times optimized "__builtin_ctz " 1 (found 0 times)
FAIL: gcc.target/i386/pr78057.c scan-tree-dump-times optimized "__builtin_ctzll " 1 (found 0 times)
FAIL: gcc.target/x86_64/abi/ms-sysv/ms-sysv.c -mcall-ms2sysv-xlogues -O2 "-DGEN_ARGS=-p1" (test for excess errors)
FAIL: gcc.target/x86_64/abi/ms-sysv/ms-sysv.c -mcall-ms2sysv-xlogues -O2 "-DGEN_ARGS=-p5" (test for excess errors)
FAIL: gcc.target/x86_64/abi/ms-sysv/ms-sysv.c  -O2 "-DGEN_ARGS=-p1" (test for excess errors)
FAIL: gcc.target/x86_64/abi/ms-sysv/ms-sysv.c  -O2 "-DGEN_ARGS=-p5" (test for excess errors)