[PATCH, i386, AVX-512] Update extract_even_odd w/ AVX-512BW insns.

[Dominique d'Humières]

Kirill,

The new tests fail on x86_64-apple-darwin14:

FAIL: gcc.target/i386/vect-pack-trunc-1.c (test for excess errors)
UNRESOLVED: gcc.target/i386/vect-pack-trunc-1.c compilation failed to produce executable
FAIL: gcc.target/i386/vect-pack-trunc-2.c (test for excess errors)
UNRESOLVED: gcc.target/i386/vect-pack-trunc-2.c compilation failed to produce executable
FAIL: gcc.target/i386/vect-perm-even-1.c (test for excess errors)
UNRESOLVED: gcc.target/i386/vect-perm-even-1.c compilation failed to produce executable
FAIL: gcc.target/i386/vect-perm-odd-1.c (test for excess errors)
UNRESOLVED: gcc.target/i386/vect-perm-odd-1.c compilation failed to produce executable
FAIL: gcc.target/i386/vect-unpack-1.c (test for excess errors)
UNRESOLVED: gcc.target/i386/vect-unpack-1.c compilation failed to produce executable
FAIL: gcc.target/i386/vect-unpack-2.c (test for excess errors)
UNRESOLVED: gcc.target/i386/vect-unpack-2.c compilation failed to produce executable

I think the tests should be protected with

/* { dg-require-effective-target avx512bw } */

Note also that the options '-fno-diagnostics-show-caret -fdiagnostics-color=never -O2’ are not obeyed:

^[[1mvect-pack-trunc-1.s:67:2: ^[[0;1;31merror: ^[[0m^[[1minstruction requires: AVX-512 ISA
^[[0m        vmovdqa64       LC0-L1$pb(%ebx), %zmm0
^[[0;1;32m        ^
^[[0m^[[1mvect-pack-trunc-1.s:68:2: ^[[0;1;31merror: ^[[0m^[[1minstruction requires: AVX-512 ISA
^[[0m        vmovdqa64       LC1-L1$pb(%ebx), %zmm4
^[[0;1;32m        ^
…

Dominique