contrib/llvm-project: re-add clang/tools/clang-scan-deps

This is in preparation for adding it as an optional tool in base.

MFC after:	1 week

contrib/llvm-project/FREEBSD-Xlist

@@ -129,7 +129,7 @@ clang/tools/clang-offload-packager/
 clang/tools/clang-refactor/
 clang/tools/clang-rename/
 clang/tools/clang-repl/
-clang/tools/clang-scan-deps/
+clang/tools/clang-scan-deps/CMakeLists.txt
 clang/tools/clang-shlib/
 clang/tools/diag-build/
 clang/tools/diagtool/
@@ -805,7 +805,6 @@ llvm/tools/llvm-bcanalyzer/CMakeLists.txt
 llvm/tools/llvm-c-test/
 llvm/tools/llvm-cat/
 llvm/tools/llvm-cfi-verify/
-llvm/tools/llvm-cgdata/
 llvm/tools/llvm-config/
 llvm/tools/llvm-cov/CMakeLists.txt
 llvm/tools/llvm-cvtres/

contrib/llvm-project/clang/tools/clang-scan-deps/Opts.td

@@ -0,0 +1,42 @@
+include "llvm/Option/OptParser.td"
+
+class F<string name, string help> : Flag<["-"], name>, HelpText<help>;
+class Arg<string name, string help> : Separate<["-"], name>, HelpText<help>;
+
+multiclass Eq<string name, string help> {
+    def NAME #_EQ : Joined<["-", "--"], name #"=">, HelpText<help>;
+    def : Separate<["-", "--"], name>, Alias<!cast<Joined>(NAME #_EQ)>;
+}
+
+def help : Flag<["--"], "help">, HelpText<"Display this help">;
+def version : Flag<["--"], "version">, HelpText<"Display the version">;
+
+def o : Arg<"o", "Destination of the primary output">;
+
+defm mode : Eq<"mode", "The preprocessing mode used to compute the dependencies">;
+
+defm format : Eq<"format", "The output format for the dependencies">;
+
+defm module_files_dir : Eq<"module-files-dir",
+    "The build directory for modules. Defaults to the value of '-fmodules-cache-path=' from command lines for implicit modules">;
+
+def optimize_args_EQ : CommaJoined<["-", "--"], "optimize-args=">, HelpText<"Which command-line arguments of modules to optimize">;
+def eager_load_pcm : F<"eager-load-pcm", "Load PCM files eagerly (instead of lazily on import)">;
+
+def j : Arg<"j", "Number of worker threads to use (default: use all concurrent threads)">;
+
+defm compilation_database : Eq<"compilation-database", "Compilation database">;
+defm module_name : Eq<"module-name", "the module of which the dependencies are to be computed">;
+defm dependency_target : Eq<"dependency-target", "The names of dependency targets for the dependency file">;
+
+def deprecated_driver_command : F<"deprecated-driver-command", "use a single driver command to build the tu (deprecated)">;
+
+defm resource_dir_recipe : Eq<"resource-dir-recipe", "How to produce missing '-resource-dir' argument">;
+
+def print_timing : F<"print-timing", "Print timing information">;
+
+def verbose : F<"v", "Use verbose output">;
+
+def round_trip_args : F<"round-trip-args", "verify that command-line arguments are canonical by parsing and re-serializing">;
+
+def DASH_DASH : Option<["--"], "", KIND_REMAINING_ARGS>;