This is done early so we can resolve the inner framework, inside the
xcframework, and let the existing framework support do most of the
work.
The resolving code has unit tests. Custom projects for "NoEmbedding"
exists for all supported platforms and executed by xharness.
A sample `xcframework` with tests projects is also available
[here](https://github.com/spouliot/xcframework).
The xcframework test case is based on Rolf's earlier/partial implementation.
https://github.com/rolfbjarne/xamarin-macios/commit/xcframework
Things to note:
Do not rename a framework (like XTest) to use it in an xcframework
(like XCTest). That will fail at codesign but won't give anything
useful. You might think signing the framework (instead of the inner
binary) would solve it. It does, as it codesign, but then the app
crash at startup. At some point you realize some symbols are still
using XTest (not XCTest) and then you can delete several other weird
workarounds (like for `ld`) because all of it was cause by this
never identified rename.
dSYM support (and tests) to be done in a separate PR.
3bd14c3eef