[Issue 18865] Add x86 SIMD Intrinsics to druntime

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=18865

--- Comment #2 from ponce <aliloko at gmail.com> ---
Since then, added support for:
    tmmintrin.h
    smmintrin.h
    nmmintrin.h

And a few others that are only partially done.

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