This adds the following new arrays, which together capture all direct
dependencies and interface dependencies of a target:
- linkLibraries
- interfaceLinkLibraries
- compileDependencies
- interfaceCompileDependencies
- objectDependencies
- orderDependencies
Fixes: #21995, #25213
When targeting the MSVC ABI, define `_MBCS` by default if the project
does not define `_SBCS` or `_UNICODE`. Visual Studio has long defined
one of the three character set macros automatically. For consistency,
define it when compiling for the MSVC ABI with other generators.
Add policy CMP0204 for compatibility.
Fixes: #27275
