- Remove code signing requirements for non-macOS
- Do not set deployment target for non-macOS
- Build static library for compiler feature detection for non-macOS
- Use framework to run CompilerId tests for watchOS
- Port tests to new SDK handling
- Add new Apple cross-compiling section to toolchain documentation
Closes: #17870
If list of valid target architectures is empty for given SDK then there will
be no VALID_ARCHS build setting returned by Xcode. Return "" (empty string)
explicitly in this case. This may happens if CMAKE_IOS_INSTALL_COMBINED is ON
but only one architecture used in target.