Update to upstream version '1.30.0'
with Debian dir a5c42db375a7f18646751c5d1a2a7536d0c94d99

Update to upstream version '1.29.0'
with Debian dir 4a4e696724bb7c1993719cc6f9223dbb2c47868b

Update to upstream version '1.28.1'
with Debian dir 3b1c055f59051afb077e44910c8f99588f1de98a

Bring back some copyright lines that were deleted by accident.

This is unsupported with LLVM >=12 and generally only considered an
experimental personal project [1] by the Author.

[1]: https://github.com/ldc-developers/ldc/issues/3747



Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>

Update to upstream version '1.28.0'
with Debian dir a5fc3c4ef7094cd02926ff19d620d6a04463469d

This patch also triggers a cmake config issue which causes the build to
fail, annoyingly.