lang/phantomjs: Allow building on armv6 and armv7 platforms
- Patches for armv6 and armv7 are obtained from www/webkit-gtk3
- Allow building with non-default LOCALBASE
- Fix build with Clang 6.0.0 [0]
PR: 225482 [0]
Reviewed by: koobs, feld
Approved by: koobs (mentor), feld (maintainner)
Differential Revision: https://reviews.freebsd.org/D15850