Alright, I installed VC2010 (with x64 libs) and added the -m64 option to the compiler. Sadly the compiler dies with the below message. Should I file a bug or did I miss something?
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Building: Easy (Debug)

Performing main compilation...

Current dictionary: C:\Users\dunlap\Documents\GitHub\CodeEval\Dlang\

C:\D\dmd2\windows\bin\dmd.exe -debug -gc "main.d" "SIMDTests.d"  "-IC:\D\dmd2\src\druntime\src" "-IC:\D\dmd2\src\phobos" "-odobj\Debug" "-ofC:\Users\dunlap\Documents\GitHub\CodeEval\Dlang\bin\Debug\SIMDTests.exe" -m64

Internal error: ..\ztc\cgcv.c 2162

Exit code 1

Build complete -- 1 error, 0 warnings