WebEngine build fails on Windows 8.1; out of disk space

The webengine build in the 5.6 branch fails on Windows 8.1 x86-64 with an out-of-disk-space error:

c:\users\qt\work\qt\qtwebengine\src\3rdparty\chromium\content\browser\frame_host\render_frame_message_filter.cc : fatal error C1085: Cannot write compiler generated file: 'obj\src\3rdparty\chromium\content\browser\frame_host\content_browser.render_frame_message_filter.obj': No space left on device

The disk is an 80GB disk that has about 30GB free (out of the box).

We should close this issue when either

(1) We have changed the tier1 images in vsphere to have bigger disks (per Tony's suggestion)

or

(2) We have completed the transition away from vsphere by having done the last export, done a manual resizing (via qemu-nbd/fdisk/ntfsresize) and delete the tier1 in vsphere.

But as long as we may be copying over the image with the disk that is too small, we should keep this issue open.