[AVX2] PATCH: Improved error reporting for AVX2 immediates in vextracti/inserti128. New tests.

[Kirill Yukhin]

Hi,
I added spcial case for immediate expanding of vinserti128 and
vextractf128 (AVX2) to improve error reporting.
Also I added bunch of new tests to check error reporting of out of
range immediates for AVX2.

ChangeLog.avx2 entry:
2011-06-20  Yukhin Kirill  <kirill.yuk...@intel.com>

        * gcc/config/i386/i386.c (ix86_expand_args_builtin): Improved
        error diagnistic for extracti128/inserti128 immediates.

tesuite/ChangeLog.avx2 entry:
2011-06-20  Yukhin Kirill  <kirill.yuk...@intel.com>

        * gcc.target/i386/avx2-mpsadbw-3.c: New test to check error
        diagnostic while passing wrong immediate.
        * gcc.target/i386/avx2-vextracti128-3.c: Likewise.
        * gcc.target/i386/avx2-vinserti128-3.c: Likewise.
        * gcc.target/i386/avx2-vpalignr256-3.c: Likewise.
        * gcc.target/i386/avx2-vpblendd128-3.c: Likewise.
        * gcc.target/i386/avx2-vpblendd256-3.c: Likewise.
        * gcc.target/i386/avx2-vpblendw-3.c: Likewise.
        * gcc.target/i386/avx2-vperm2i128-3.c: Likewise.
        * gcc.target/i386/avx2-vpermpd-3.c: Likewise.
        * gcc.target/i386/avx2-vpermq-3.c: Likewise.
        * gcc.target/i386/avx2-vpshufd-3.c: Likewise.
        * gcc.target/i386/avx2-vpshufhw-3.c: Likewise.
        * gcc.target/i386/avx2-vpshuflw-3.c: Likewise.
        * gcc.target/i386/avx2-vpslldq-3.c: Likewise.
        * gcc.target/i386/avx2-vpsrldq-3.c: Likewise.

Going to commit to avx2 branch.

Thanks, K