build error (and suggested fix): add ARCHIVE DESTINATION for static libs

In my environment I hit build errors with the following two lines of CMakeLists.txt;
https://github.com/virtualsquare/s2argv-execs/blob/40f86a21ff242cac17303ea93169fe87812638ee/CMakeLists.txt#L34-L35

For those two targets (the only ones declared as static libraries), it seems cmake needed ARCHIVE DESTINATION, in addition to (or instead of) LIBRARY DESTINATION.

The following local change allows the build to complete successfully;

 install(TARGETS execs LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
 install(TARGETS execs-embedded LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
-install(TARGETS execs_static LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
-install(TARGETS execs-embedded_static LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+install(TARGETS execs_static LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+       ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
+install(TARGETS execs-embedded_static LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+       ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
 install(FILES execs.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})

Start with CMakeLists.txt lines 34-35, which install the two static-library targets execs_static and execs-embedded_static. Check the CMake install behavior for static libraries and apply the proposed ARCHIVE DESTINATION change. Done means the project configures, builds, and installs successfully in the affected environment.