[Driver] Remove Joined -Z and err_drv_use_of_Z_option

This takes a detour to report an error, but we can just remove Joined -Z
which is rejected by GCC.

Author: MaskRay

clang/include/clang/Basic/DiagnosticDriverKinds.td

@@ -128,8 +128,6 @@ def err_drv_invalid_stdlib_name : Error<
 def err_drv_invalid_output_with_multiple_archs : Error<
   "cannot use '%0' output with multiple -arch options">;
 def err_drv_no_input_files : Error<"no input files">;
-def err_drv_use_of_Z_option : Error<
-  "unsupported use of internal gcc -Z option '%0'">;
 def err_drv_output_argument_with_multiple_files : Error<
   "cannot specify -o when generating multiple output files">;
 def err_drv_out_file_argument_with_multiple_sources : Error<

clang/include/clang/Driver/Options.td

@@ -844,8 +844,6 @@ def Xpreprocessor : Separate<["-"], "Xpreprocessor">, Group<Preprocessor_Group>,
   HelpText<"Pass <arg> to the preprocessor">, MetaVarName<"<arg>">;
 def X_Flag : Flag<["-"], "X">, Group<Link_Group>;
 def Z_Flag : Flag<["-"], "Z">, Group<Link_Group>;
-// FIXME: All we do with this is reject it. Remove.
-def Z_Joined : Joined<["-"], "Z">;
 def all__load : Flag<["-"], "all_load">;
 def allowable__client : Separate<["-"], "allowable_client">;
 def ansi : Flag<["-", "--"], "ansi">, Group<CompileOnly_Group>;

clang/lib/Driver/Driver.cpp

@@ -3869,11 +3869,6 @@ void Driver::BuildActions(Compilation &C, DerivedArgList &Args,
     return;
   }
 
-  // Reject -Z* at the top level, these options should never have been exposed
-  // by gcc.
-  if (Arg *A = Args.getLastArg(options::OPT_Z_Joined))
-    Diag(clang::diag::err_drv_use_of_Z_option) << A->getAsString(Args);
-
   // Diagnose misuse of /Fo.
   if (Arg *A = Args.getLastArg(options::OPT__SLASH_Fo)) {
     StringRef V = A->getValue();