MFC r345316, r345317, r345858:

r345316: Register ARM64 EC2 AMIs as being for the ARM64 architecture.

r345317: Don't install amazon-ssm-agent package into ARM64 AMIs.

r345858: Add support for cross-building cloudware images.

With these changes it is possible to build ARM64 EC2 AMIs on stable/12 --
said images do not *work* yet, however.

MFC r336420,336433,336593,336621,336622,336624,337394,337401,338141

Teach the EC2 AMI upload code to:
* Mark EBS snapshots as public,
* Announce new AMIs to an SNS topic, and
* Place the SVN branch and revision into the AMI "description".

MFC r318894: Enable Amazon's "Elastic Network Adapter" in EC2 AMIs.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add 'env - PATH=$$PATH' to bsdec2-image-upload make command, in order to
avoid environment pollution problems. That port uses <bsd.prog.mk> but
is not compatible with the latest mk bits in HEAD.

Reported by: gjb
No rush, but make sure it's in the tree before tomorrow by: gjb

Enable "EC2 Enhanced Networking" (aka. SR-IOV networking) when creating
EC2 images.

X-MFC after: if/when the driver fixes get MFCed
Relnotes: FreeBSD now supports EC2 Enhanced Networking

Remove the HH-MM suffix from the build date suffix.

It was useful when working out several kinks when
testing automated image uploading when retrying was
necessary, but now it is making things much too messy.

MFC after: 3 days
Sponsored by: The FreeBSD Foundation

Change the hour:minute delimiter from ':' to '-', since
the former is an invalid character in EC2 images.

MFC after: 3 days
Sponsored by: The FreeBSD Foundation

Consider PRERELEASE builds snapshots, in addition to CURRENT and
STABLE.

MFC after: 3 days
Sponsored by: The FreeBSD Foundation

Append the hour and minute to the snapshot suffix for EC2
AMIs and Azure VM images. This is particularly helpful for
testing to avoid name collisions, but also useful for cases
where a necessary rebuild is done before the date changes.

MFC after: 3 days
Sponsored by: The FreeBSD Foundation

Remove trailing tabs to avoid spamming stdout with long lines.

MFC after: 3 days
Sponsored by: The FreeBSD Foundation

Include the TARGET in the EC2 AMI name.

Without this, AWS rejects subsequent image uploads of a different
architecture because the name conflicts.

MFC after: 3 days
Sponsored by: The FreeBSD Foundation

Remove a debugging line that snuck in with r282419.

Pointyhat: gjb
MFC after: 3 days
X-MFC-With: r282419
Sponsored by: The FreeBSD Foundation

Add logic to detect if the net/bsdec2-image-upload port needs
to be installed. [1]

For the cw-ec2-portinstall and ec2ami targets, touch the
.TARGET file after completion to prevent duplicate invocations.

Add cw-ec2-portinstall and ec2ami to CLEANFILES.

Submitted by: cperciva[1]
MFC after: 3 days
Sponsored by: The FreeBSD Foundation

Add the cw-ec2-portinstall target to always install the
net/bsdec2-image-upload port.

MFC after: 3 days
Sponsored by: The FreeBSD Foundation

Add code for creating an EC2 AMI.