* Remove more usage of mcs across the build and tests
* Fix -o[ut] mcs/csc argument difference
* Fix OpenTK.[dll.mdb|pdb]
* Complete some MCS|CSC renames
* Fix SYSTEM_CSC not to have a default option since it's not usable that way in every case (and most of them already deal with that option)
* Do not rename a variable used by mono itself
* Un-renamed two other variables
* Fix copying pdb
* Generate debug symbols for *.BindingAttributes.dll and copy .mdb for the old XamMac binary version
* Newer csc-compiled XamMac.BindingAttributes.dll have .pdb while the old, mcs-compiled binary cached, version has a .mdb
* Fix msc -> mcs typo.
* [mtouch] Don't allow building for 32-bit when deployment target is >= 11. Fixes#57966.
Also bump maccore to get an mlaunch error for launching a 32-bit app in a 64-bit-only simulator.
https://bugzilla.xamarin.com/show_bug.cgi?id=57966
* [tests][msbuild] Make sure all Info.plists have deployment targets.
Otherwise we get different behavior (32-bit allowed or not) depending on which
Xcode is used to build.
* [mtouch] Default to 64-bit arch if not specified and targeting iOS 11+.
* [tests] Tweak tests to either specify a deployment target < 11 or not build a 32-bit arch.
* [tests] Remove Classic SDK tests.
* Remove XI/Classic support.
This also means we can remove support for the legacy registrars.
* [monotouch-test] Remove legacy registrar tests.
* [tests/mtouch] Remove Classic tests (and legacy registrar logic).
* [tests/scripted] Fix tests to reference Xamarin.iOS.dll.
Sebastien Pouliot
Rolf Bjarne Kvinge