x86-64: fix pointer size in Golang AMD64p32 ABI
x86-64: fix pointer size in Golang AMD64p32 ABI

pombredanne/PeachPy,lemire/PeachPy,adamzhz/PeachPy,shaunstanislaus/PeachPy,utensil-star/PeachPy,silky/PeachPy