A few updates to enable building on Raspberry PI/Ubuntu 16.04

[nettlep]

I ran into some compilation failures while building on the Raspberry PI Model 3. These issues were simply type conversion warnings that resulted in errors (due to -Werror in the compilation settings.)

There may be more related issues, but what is attached is the minimal set of changes required to get it to build for me.

My setup: Raspberry PI 3 Model B

$ uname -a
Linux rpi 4.9.37-v7+ #1017 SMP Thu Jul 13 11:26:04 BST 2017 armv7l armv7l armv7l GNU/Linux

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.3 LTS
Release:        16.04
Codename:       xenial

${SRCROOT}/swift/utils/build-script --preset=buildbot_linux_1604 install_destdir="${SRCROOT}/__install"  installable_package="${SRCROOT}/__install.tar.gz"

My apologies for not providing the exact compilation error output. It would take hours to produce those errors. If they are needed, I can restart that process to do so.

[MadCoder]

this should be uint64_t

[MadCoder]

This looks good, please squash the branch so that I can merge it.

[MadCoder]

@swift-ci test

[nettlep]

Done, I think? Let me know if I didn't do that right.

[MadCoder]

Nope it says 4 commits, should be just the one

[MadCoder]

1. git fetch
2. git rebase -i origin master
3. leave pick of your original commit there and prefix the second one with fixup drop any other line
4. exit editor and force-push

[nettlep]

Okay, the 'git rebase -i origin master' provided just a single 'noop' entry. So I rebased like normal but used your pick/fixup instruction and it looks like that got it right.

Sorry 'bout this. It's not your job to teach git. Appreciate it, though.