add .gitignore file to ignore backup files and update arm-androideabi scripts again
Signed-off-by: Paul Beeler <sparksco@gmail.com>

Change-Id: Ie70b154450db119871723adf944bcc0601325f22
Revert "gcc: disable libquadmath"

This reverts commit 004261d3bda2fde5cdb823818edcaddf1deef7dd.