Flagless cross compile builds

[prestonvanloon]

It seems we have to build cross compile invocations for each OS/arch pair, rather than invoking a build in a single command.

Blocked by bazelbuild/bazel#6519

What we have:

bazel build --platforms=@io_bazel_rules_go//go/toolchain:linux_amd64_cgo //beacon-chain //validator
bazel build --platforms=@io_bazel_rules_go//go/toolchain:linux_arm64_cgo //beacon-chain //validator
bazel build --platforms=@io_bazel_rules_go//go/toolchain:darwin_amd64_cgo //beacon-chain //validator
bazel build --platforms=@io_bazel_rules_go//go/toolchain:windows_amd64_cgo //beacon-chain //validator

What we want:

bazel build //:all_binaries_bundle

Which would produce a zip / tar with distros for each system.

[prestonvanloon]

Update: I have an idea to try from this comment: bazelbuild/bazel#6519 (comment)

Haven't had the time to attempt it yet.

[rauljordan]

Done by @SuburbanDad