Commonly used Android toolchain files that pre-date CMake upstream
support may need to be updated to work with our new functionality.
They typically set CMAKE_SYSTEM_VERSION to 1, so detect that and
skip our upstream Android settings. When such toolchain files are
updated to account for our upstream support, they can then set
CMAKE_SYSTEM_VERSION to a valid Android API and get new behavior.
Compute CMAKE_SYSROOT automatically for the current API and architecture
selection. This causes the --sysroot option to be passed to GNU and
Clang compilers.
Support for NVIDIA Nsight Tegra Visual Studio Edition was previously
implemented in the CMake VS IDE generators. Avoid interfering with
that functionality for now. Later we may try to integrate this.
Brad King