dev/beber/build: improve install target (#150)

* build: remove hardcoded lib/ destination

cmake internally has a logic to know where is the best place to install
a given library. For example on amd64 it does not make sense to install
the library in /usr/lib, this change allow the library to the installed
in /usr/lib64

* build: mark src/randomx.h as a public header

this allow src/randomx.h to be installed in /usr/include/randomx.h
automagically during make install

CMakeLists.txt

@@ -157,9 +157,10 @@ add_library(randomx
 set_property(TARGET randomx PROPERTY POSITION_INDEPENDENT_CODE ON)
 set_property(TARGET randomx PROPERTY CXX_STANDARD 11)
 set_property(TARGET randomx PROPERTY CXX_STANDARD_REQUIRED ON)
+set_property(TARGET randomx PROPERTY PUBLIC_HEADER src/randomx.h)
 install(TARGETS randomx
-  ARCHIVE DESTINATION lib
-  LIBRARY DESTINATION lib)
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
 add_executable(randomx-tests
   src/tests/tests.cpp)