Previously, https://github.com/flutter/flutter/pull/100271 enabled
building universal macOS binaries by default, but included a bug causing
the arm64 App.framework to be built such that the TEXT section
containing the app instructions built by gen_snapshot incorrectly
contained x86_64 instructions rather than arm64 instructions.

When building macOS (and iOS) apps, Flutter builds them in three
components:
* The Runner application: built by Xcode
* The bundled App.framework: built from assembly code generated by
  gen_snapshot from the application's Dart sources.
* The bundled FlutterMacOS.framework: built as part of the engine build
  and packaged by copying the distributed binary framework from our
  artifacts cache.

Building App.framework consists of the following steps:
* For each architecture, invoke gen_snapshot to generate
  architecture-specific assembly code, which is then built to object
  code and linked into an architecture-specific App.framework.
* Use the `lipo` tool to generate a universal binary that includes both
  x86_64 and arm64 architectures.

Previously, we were building architecture specific App.framework
binaries. However, for all architectures we were (mistakenly) invoking
the general `gen_snapshot` tool (which emitted x64 instructions, and
which is now deprecated) instead of the architecture-specific
`gen_snapshot_x86` and `gen_snapshot_arm64` builds which emit
instructions for the correct architecture.

This change introduces a small refactoring, which is to split the
`getNameForDarwinArch` function into two functions:
* `getDartNameForDarwinArch`: the name for the specified architecture as
  used in the Dart SDK, for example as the suffix of `gen_snapshot`.
* `getNameForDarwinArch`: the name for the specified architecture
  as used in Apple tools, for example as an argument to `lipo`. For
  consistency, and to match developer expectations on Darwin platforms,
  this is also the name used in Flutter's build outputs.

Issue: https://github.com/flutter/flutter/issues/100348

This reverts commit 8b6baae4.

Our current top crasher is an unclear error when ProcessManager fails to resolve an executable path. To fix this, we'd like to being adjusting the process resolution logic and adding more instrumentation to track failures. In order to begin the process, the ProcessManager has been folded back into the flutter tool

* opt out the flutter tool

* oops EOF

* fix import

* Update tool_backend.dart

* Update daemon_client.dart

* fix more

There have been some more additional reports of a missing 'package:characters' import after upgrading flutter. This has me concerned that our pub caching logic is incorrect. Instead of the tool attempting to guess when pub should be run, always delegate to pub.

Also takes an opportunity to fix the kernel snapshot depending on the .packages or package_config. Due to the generated: date field this causes extra rebuilds. Instead when pub get is run, write out an additional file with just the package contents and version.

Fixes #66777
Fixes #65723

* App.framework must support iOS 8 for older Flutter projects

* Fix test

Revert "[flutter_tools] separate target platform, host platform, and architecutre (#60119)" (#60147)

This reverts commit 30d97d89.

separate target platform, host platform, and architecture

Builds and bundles an 'app.so' containing AOT data, and downloads and packages the release/profile artifacts for those builds, rather than always using the debug artifacts.

Fixes https://github.com/flutter/flutter/issues/38477
Fixes https://github.com/flutter/flutter/issues/39664

Reland of #52091

This reverts commit f65421aa.

Remove dependency injection from GenSnapshot and AotBuilder and update tests to use FakeProcessManager

This reverts commit 8e6e15f9.