Enable flutter engine artifacts for Windows on Arm

[pbo-linaro]

Use case

To support targeting Windows on Arm platform (#62597), we need first to enable artifacts for flutter engine on this platform.

Proposal

Engine can be cross-compiled from a x64 machine by using:

python3 ./flutter/tools/gn --no-goma --windows-cpu arm64
ninja -C out/host_debug_arm64

I'll create a patch for recipe file.
Thanks @loic-sharma for proposing to help upstream this patch.

[pbo-linaro]

@loic-sharma Tried to create a gerrit change for that, but it confirms I don't have access.

The commit to upstream is here, based on what was done for darwin-arm64.

[loic-sharma]

Hello, thanks for the patch! I apologize for the delay, I was off last week.

I kicked off a test run of your changes, that failed on the Zip windows-arm64 windows-arm64-embedder.zip step:

IOError: [Errno 2] No such file or directory: u'C:\b\s\w\ir\cache\builder\src\out/host_debug_arm64/flutter_embedder.h'

Please let me know when you're ready for me to run another test!

[pbo-linaro]

Thanks @loic-sharma . No problem, you said you were out :)

I pushed two other commits here, to fix the issue you mentioned (regarding font), and removed the embedder package for now (not sure what it is used for).

Feel free to squash commits to have a single patch. For now, I just try to keep commits splitted to track history of this patch.

[loic-sharma]

Here's the latest result: https://ci.chromium.org/raw/build/logs.chromium.org/flutter/led/loicsharma_google.com/c0e4ff1860fc1c4916a177502cc4cfb0fad1d20aa848aac5b68add72334199f0/+/build.proto?server=chromium-swarm.appspot.com

( 321 ms )C:\b\s\w\ir\cache\builder\src\out\host_release_arm64\zip_archives\windows-arm64\font-subset.zip not found
( 319 ms )Files in parent directory of safe_upload request
[WinError 3] The system cannot find the path specified: 'C:\b\s\w\ir\cache\builder\src\out\host_release_arm64\zip_archives\windows-arm64'

[pbo-linaro]

I removed the font subset as it does not seem to be built when building for windows-arm64. Still here.

[loic-sharma]

Here's the latest build: https://ci.chromium.org/raw/build/logs.chromium.org/flutter/led/loicsharma_google.com/b765281e408ff608bc165ac7291626f93782efeac52f2d4936eb64a7482f9847/+/build.proto?server=chromium-swarm.appspot.com

It looks like it passed! (The final step fails, but that seems like an unrelated permission issue)

[pbo-linaro]

Ok great! I squashed all commits, and rebased it on top of master.

Could you submit it for review please, and post the link here?