Fix Win64 ABI wrt. passing structs > 64 bit
Merge pull request #756 from kinke/abi

Fix Win64 ABI wrt. passing structs > 64 bit
Win64 ABI hotfix
Merge pull request #757 from kinke/abifix

Win64 ABI hotfix
std.math: use most inline x86/x64 assembly only if real is defined as x87