Userspace: Add shared library test

I will use this while testing my dynamic loader

userspace/tests/test-shared/CMakeLists.txt

@@ -0,0 +1,8 @@
+set(SOURCES
+	main.cpp
+)
+
+add_executable(test-shared ${SOURCES})
+banan_link_library(test-shared libc-shared)
+
+install(TARGETS test-shared OPTIONAL)