Add a cross-file for MSVC UWP ARM64.
Bump cidata tag to get an updated install.ps1 script (run by run.ps1)
which sets the vcvars environment correctly when cross-compiling.
Since arranging the correct environment for simultaneous cross and
native 'cl' use is hard, this is test run uses '--cross-only' so we
don't require a native compiler.
Extend '--cross-only' so it also explicitly uses a machine file which
makes all build machine compilers unusable.
D lang compilers have an option -release (or similar) which turns off
asserts, contracts, and other runtime type checking. This patch wires
that up to the b_ndebug flag.
Fixes#7082