Add suppress_warnings.cmake

Much of our codebase is third-party code that does not follow Apple's
current coding guidelines, especially around the use of sprintf(). This
macro will help development by limiting the warnings to only our code,
once I apply it next commit.

CMakeLists.txt

@@ -23,6 +23,7 @@ include(cmake/get_target_dependencies.cmake)
 include(cmake/install_helpers.cmake)
 include(cmake/kext.cmake)
 include(cmake/mig.cmake)
+include(cmake/suppress_warnings.cmake)
 
 add_subdirectory(projects)
 add_subdirectory(src)

cmake/suppress_warnings.cmake

@@ -0,0 +1,4 @@
+macro(suppress_warnings target)
+    target_compile_options(${target} PRIVATE -w)
+    target_link_options(${target} PRIVATE -w)
+endmacro()