Output directory in which to build |XXX| target files.
This property specifies the directory into which |xxx| target files
should be built. The property value may use
generator expressions.
Multi-configuration generators (Visual Studio,
Xcode, Ninja Multi-Config) append a
per-configuration subdirectory to the specified directory unless a generator
expression is used.
This property is initialized by the value of the |CMAKE_XXX_OUTPUT_DIRECTORY| variable if it is set when a target is created.