corrosion: Add with 0.6.1

Corrosion, formerly known as cmake-cargo, is a tool for integrating Rust into an existing CMake project. Corrosion can automatically import executables, static libraries, and dynamic libraries from a workspace or package manifest (Cargo.toml file).

Fixes
Fix building shared libraries for iOS.
Fix host linker detection for iOS and add the CORROSION_HOST_TARGET_LINKER cache variable, to allow users to override the linker used for the host build (required for build-scripts and proc-macros).
