[CMake] Ignore None and NoneType deprecations

`llvm::None` is deprecated, but still being used in Swift until we have
fewer 5.10 cherry-picks. Add the `SWIFT_TARGET` definition to ignore the
deprecation.

Author: bnbarham

SwiftCompilerSources/CMakeLists.txt

@@ -103,7 +103,7 @@ function(add_swift_compiler_modules_library name)
       "-Xfrontend" "-enable-experimental-cxx-interop"
       "-Xfrontend" "-disable-target-os-checking"
       "-Xcc" "-std=c++17"
-      "-Xcc" "-DCOMPILED_WITH_SWIFT"
+      "-Xcc" "-DCOMPILED_WITH_SWIFT" "-Xcc" "-DSWIFT_TARGET"
       "-Xcc" "-UIBOutlet" "-Xcc" "-UIBAction" "-Xcc" "-UIBInspectable")
   if (NOT BOOTSTRAPPING_MODE STREQUAL "HOSTTOOLS")
     list(APPEND swift_compile_options "-Xfrontend" "-disable-implicit-string-processing-module-import")
@@ -271,6 +271,7 @@ else()
   file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/HeaderDependencies.cpp.tmp"
        "
 #define COMPILED_WITH_SWIFT
+#define SWIFT_TARGET
 
 #include \"Basic/BasicBridging.h\"
 #include \"SIL/SILBridging.h\"

lib/ASTGen/CMakeLists.txt

@@ -102,7 +102,7 @@ endif()
 set(compile_options
   ${c_include_paths_args}
   "SHELL: ${cxx_interop_flag}"
-  "SHELL: -Xcc -std=c++17 -Xcc -DCOMPILED_WITH_SWIFT"
+  "SHELL: -Xcc -std=c++17 -Xcc -DCOMPILED_WITH_SWIFT -Xcc -DSWIFT_TARGET"
 
   # FIXME: Needed to work around an availability issue with CxxStdlib
   "SHELL: -Xfrontend -disable-target-os-checking"