Arch Linux

Description:

(Not sure if I should have posted in the forum first)
This morning I attempted to perform my normal package update and found that the newly released version of glm (glm-0.9.8.3-3-any) seemed to conflict with the filesystem package.

Originally the following packages were all being upgraded by my pacmany -Syu command:

```
Packages (15) adwaita-icon-theme-3.22.0+1+g58cd459e-1 dkms-2.3-2 glm-0.9.8.3-3 gnutls-3.5.8-2 highlight-3.34-1 libinput-1.5.4-1 libldap-2.4.44-3 libvpx-1.6.1-1 lz4-1:1.7.5-1 minizip-1:1.2.10-1 nano-2.7.4-1 perl-mouse-2.4.7-1 system-config-printer-1.5.9-1
xorg-fonts-misc-1.0.3-5 zlib-1:1.2.10-1
```

And I got the following messages:

```
error: failed to commit transaction (conflicting files)
glm: /usr/lib64 exists in filesystem
glm: /usr/lib64/cmake/glm/glmConfig.cmake exists in filesystem
glm: /usr/lib64/cmake/glm/glmConfigVersion.cmake exists in filesystem
glm: /usr/lib64/cmake/glm/glmTargets.cmake exists in filesystem
glm: /usr/lib64/pkgconfig/glm.pc exists in filesystem
Errors occurred, no packages were upgraded.
```

I attempted to upgrade glm on it's own and got the same errors.
Then attempted to reinstall filesystem and then glm, still the same errors.

I then upgraded my other packages successfully ignoring glm using the command: sudo pacman -Syu --ignore glm

Attempted the same 2 steps as before, reinstalling filesystem and then upgrading glm.
Next I removed glm: sudo pacman -R glm
And then attempted to reinstall it to which I got the following:

```
error: failed to commit transaction (conflicting files)
glm: /usr/lib64 exists in filesystem
```

I then finally reinstalled the older version of glm with no issues and started writing this bug report.

Additional info:
* Previous version of glm that was working: glm-0.9.8.3-1-any
* Current version of filesystem: filesystem-2016.12-2-x86_64
* I don't think I have any alteration to my /etc/pacman.conf apart from altering the XferCommand to use wget

Steps to reproduce:
* Install filesystem package (filesystem-2016.12-2-x86_64).
* Install previous glm version (glm-0.9.8.3-1-any)
* Attempt an upgrade of glm