How about a cross-compiler SIMD module?

[Stefanos Baziotis]

As part of my GSoC project, I wanted to use SIMD intrinsics. But 
I could not find a way to write cross-compiler code. That 
includes core.simd, but also intel-intrinsics.
Specifically intel-intrinsics is a great library, but it could 
not be used in GDC (at least I did not find a way) and it seems 
LDC focused.

So, I wrote a mini SIMD module [1]. This is not very general as 
it was targeted only for the Dmem* utilities. But then I thought, 
why not make such a module in the druntime?

In the link, you can see for example a simple store function. 
Also, it shows
the best I got as far as how to answer the question "Is SIMD 
supported?" across
compilers.

[1] 
https://github.com/dlang/druntime/pull/2687/files#diff-c2fcd73761ae6659ef91245ce1195b6dR70