```
This is a potential solution for #18456.
It seems that the compiler cannot turn
_mm_set_epi64x(<constant>,<constnant>) into a constant itself, and thus
emits a global initializer for the MASK, INIT0, and INIT1 global
constants in the sha-ni SHA256 implementation.
Change this by turning them into dumb byte arrays, loading them into an
SSE variable whenever needed.
Tested on a SHA-NI capable machine. I do not observe any obvious
performance impact (but this is hard to measure, it's already very
fast...).
```
Backport of core PR18553.