vim: syntax: Add loong64 architecture

There is an Arch Linux distro that uses the loong64 architecture[1].

This patch adds "loong64" to the list of allowed pbArch keywords and adds various {source,depends,…}_$arch to the list of .SRCINFO's srcInfoField.

[1] https://rfc.archlinux.page/0032-arch-linux-ports/

Signed-off-by: Xiaotian Wu yetist@gmail.com

mentioned in commit 328dcc18

merged

Merged, thank you!