Baseline: 1cf392ff

Cherry picks:

   + 32563ca1:
     [Skymeld] Avoid printing extra WARNINGS for execution failures
     in -k.
   + 19f5e933:
     Automated rollback of commit
     f0641847.

Incompatible changes:

  - `cmd_helper` module was removed
  - `ctx.new_file` was removed, `ctx.actions.declare_file` is to be
    used instead.
  - Fails on unknown attributes (even when set to None). See
    https://github.com/bazelbuild/bazel/issues/19403
  - Flip incompatible_enable_cc_toolchain_resolution
    (https://github.com/bazelbuild/bazel/issues/7260)

Important changes:

  - Change output paths to consistently start with
    [cpu]-[compilation_mode] along with other cleanups to output path
    generation logic.
  - Compilation actions using the auto-configured MSVC toolchain are
    forced to emit error messages in English if the English language
    pack for Visual Studio is installed.

This release contains contributions from many people at Google, as well as Benjamin Peterson, Boleyn Su, Brentley Jones, Daniel Wagner-Hall, Fabian Meumertzheim, Keith Smiley, Roman Salvador, Timothy Gu.