[Bug target/85538] kortest for 32 and 64 bit masks incorrectly uses k0

[kretz at kde dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85538

--- Comment #1 from Matthias Kretz <kretz at kde dot org> ---
Sorry, I was trying to force GCC to use the k1 register and playing with
register asm (which didn't have any effect at all). f8 should actually be (cf.
https://godbolt.org/g/hSkoJV):

bool f8(__m512i x, __m512i y) {
    __mmask64 k = _mm512_cmp_epi8_mask(x, y, _MM_CMPINT_EQ);
    return _kortestc_mask64_u8(k, k);
}