BUG: Fix numpy.random bug in platform detection

[5ghz]

BUG: fix platform detection
Wrong platfrom detection

Enviroment:
Linux host: Linux debian-cross 4.19.0-5-amd64 #1 SMP Debian 4.19.37-5+deb10u2 (2019-08-08) x86_64 GNU/Linux
Python3 version: Python 3.7.3
Pip3 version: 18.1
Debian version: 10
Numpy cross-compile on debian 10 failed because numpy detects arm platform as amd64 and add msse2 flag.

For reproduce:
Install proot and qemu
apt install proot qemu qemu-user
Download raspbian from official mirror:
wget https://downloads.raspberrypi.org/raspbian/images/raspbian-2019-07-12/2019-07-10-raspbian-buster.zip
unzip 2019-07-10-raspbian-buster.zip
Mount partion:
fdisk -l 2019-07-10-raspbian-buster.img
Need these string from output
2019-07-10-raspbian-buster.img2 540672 7380991 6840320 3.3G 83 Linux
mount -o loop,offset=$((512*540672)) 2019-07-10-raspbian-buster.img /mnt
Chroot into raspbian:
proot -R /mnt -q qemu-arm
After that:
bash
pip3 install --log=/tmp/numpy git+https://github.com/numpy/numpy.git
Chroot enviroment: Linux debian-cross 4.19.0-5-amd64 #1 SMP Debian 4.19.37-5+deb10u2 (2019-08-08) armv7l GNU/Linux

Also If you have not Intel like hardwate (e.g. raspberry pi)
You can set hostname e.g. hostname leafx86 and try to compile numpy.
Compile log in attachment:
numpy_failed.log

[rgommers]

Hmm, most of that logic is new and seems a bit out of place. This PR can be merged as is, but then we should really move most of the logic for platform detection and flag handling to numpy.distutils as much as possible (is_msvc, the LARGE_FILES stuff, etc.). /arch:SSE2 is already handled in the numpy.distutils MSVC support files.

[charris]

@rgommers Sounds like you are OK for merging this. The code is new in 1.17, if we want to make it more consistent we can do that in master and backport this.

[rgommers]

Sounds like you are OK for merging this.

indeed

The code is new in 1.17, if we want to make it more consistent we can do that in master and backport this.

no need to backport unless someone reports an actual build issue. I just noticed that it's in the wrong place and will lead to maintenance issues long-term

[charris]

@rogommers I meant just backport this fix, any different fixes can go in master later.