intel-intrinsics package, use Intel syntax for SIMD intrinsics

[Guillaume Piolat via Digitalmars-d-announce]

The idea behind this (LDC-only) package is to reuse the existing 
body of code and documentation that exist for C++ programmers, 
using the Intel x86 intrinsics name.

Available through DUB: 
http://code.dlang.org/packages/intel-intrinsics

While the syntax and portability are worse than vanilla LDC 
vector support, this allows to use the Intel's guide here: 
https://software.intel.com/sites/landingpage/IntrinsicsGuide/

So far the syntax looks pretty much identical with C++ compilers 
like MSVC, clang and ICC - except for the shifts instructions.