Allow --precompile and -fprebuilt-module-path to be passed directly into CL driver without /clang: prefix

Author: sharadhr

clang/include/clang/Driver/Options.td

@@ -3085,7 +3085,7 @@ def fmodules_user_build_path : Separate<["-"], "fmodules-user-build-path">, Grou
   HelpText<"Specify the module user build path">,
   MarshallingInfoString<HeaderSearchOpts<"ModuleUserBuildPath">>;
 def fprebuilt_module_path : Joined<["-"], "fprebuilt-module-path=">, Group<i_Group>,
-  Flags<[]>, Visibility<[ClangOption, CC1Option]>,
+  Flags<[]>, Visibility<[ClangOption, CLOption, CC1Option]>,
   MetaVarName<"<directory>">,
   HelpText<"Specify the prebuilt module path">;
 defm prebuilt_implicit_modules : BoolFOption<"prebuilt-implicit-modules",
@@ -5874,6 +5874,7 @@ def _output : Separate<["--"], "output">, Alias<o>;
 def _param : Separate<["--"], "param">, Group<CompileOnly_Group>;
 def _param_EQ : Joined<["--"], "param=">, Alias<_param>;
 def _precompile : Flag<["--"], "precompile">, Flags<[NoXarchOption]>,
+  Visibility<[ClangOption, CLOption]>,
   Group<Action_Group>, HelpText<"Only precompile the input">;
 def _prefix_EQ : Joined<["--"], "prefix=">, Alias<B>;
 def _prefix : Separate<["--"], "prefix">, Alias<B>;