Fixes for building tests with Swift enabled

Need to link the Swift runtime libraries and set rpath when
we included the Swift overlay into libdisaptch.so. If we don't,
linking the test executables will fail.

Author: dgrove-oss

tests/CMakeLists.txt

@@ -38,6 +38,9 @@ if(BSD_OVERLAY_FOUND)
                         PRIVATE
                           ${BSD_OVERLAY_LDFLAGS})
 endif()
+if(CMAKE_SWIFT_RUNTIME_LIBDIR)
+  target_link_libraries(bsdtestharness PRIVATE -L${CMAKE_SWIFT_RUNTIME_LIBDIR} -lswiftCore -lswiftSwiftOnoneSupport -Wl,-rpath -Wl,${CMAKE_SWIFT_RUNTIME_LIBDIR})
+endif()
 
 function(add_unit_test name)
   set(options DISABLED_TEST)
@@ -86,6 +89,9 @@ function(add_unit_test name)
                             ${BSD_OVERLAY_LDFLAGS})
   endif()
   target_link_libraries(${name} PRIVATE bsdtests)
+  if(CMAKE_SWIFT_RUNTIME_LIBDIR)
+	target_link_libraries(${name} PRIVATE -L${CMAKE_SWIFT_RUNTIME_LIBDIR} -lswiftCore -lswiftSwiftOnoneSupport -Wl,-rpath -Wl,${CMAKE_SWIFT_RUNTIME_LIBDIR})
+  endif()
   add_test(NAME ${name}
            COMMAND bsdtestharness $<TARGET_FILE:${name}>)
   set_tests_properties(${name}