Tests: Establish root Tests directory, move Userland/Tests there

With the goal of centralizing all tests in the system, this is a
first step to establish a Tests sub-tree. It will contain all of
the unit tests and test harnesses for the various components in the
system.

Tests/LibC/CMakeLists.txt

@@ -0,0 +1,23 @@
+set(TEST_SOURCES
+    ${CMAKE_CURRENT_SOURCE_DIR}/snprintf-correctness.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/strlcpy-correctness.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/TestLibCTime.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/TestLibCMkTemp.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/TestLibCExec.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/TestLibCDirEnt.cpp
+)
+
+file(GLOB CMD_SOURCES  CONFIGURE_DEPENDS "*.cpp")
+list(REMOVE_ITEM CMD_SOURCES ${TEST_SOURCES})
+
+# FIXME: These tests do not use LibTest
+foreach(CMD_SRC ${CMD_SOURCES})
+    get_filename_component(CMD_NAME ${CMD_SRC} NAME_WE)
+    add_executable(${CMD_NAME} ${CMD_SRC})
+    target_link_libraries(${CMD_NAME} LibCore)
+    install(TARGETS ${CMD_NAME} RUNTIME DESTINATION usr/Tests/LibC)
+endforeach()
+
+foreach(source ${TEST_SOURCES})
+    serenity_test(${source} LibC)
+endforeach()