make the old -fdepscan-prefix-map= option driver-only

Author: sina-mahdavi

clang/include/clang/Driver/Options.td

@@ -8836,7 +8836,7 @@ def fdepscan_include_tree : Flag<["-"], "fdepscan-include-tree">,
 //
 // FIXME: Add DepscanOption flag.
 def fdepscan_prefix_map_EQ : Joined<["-"], "fdepscan-prefix-map=">,
-    Group<f_Group>, Visibility<[ClangOption, CC1Option]>,
+    Group<f_Group>, Visibility<[ClangOption]>,
     MetaVarName<"<old>=<new>">,
     HelpText<"With -fdepscan, seamlessly filter the CAS filesystem to"
              " apply the given prefix, updating the command-line to match.">;

clang/lib/Frontend/CompilerInvocation.cpp

@@ -3391,12 +3391,6 @@ static bool ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
     assert(Values.size() == 2);
     Opts.PathPrefixMappings.emplace_back(Values[0], Values[1]);
   }
-  for (const Arg *A : Args.filtered(OPT_fdepscan_prefix_map_EQ)) {
-    StringRef Val = A->getValue();
-    if (std::optional<llvm::MappedPrefix> mapping = llvm::MappedPrefix::getFromJoined(Val)) {
-      Opts.PathPrefixMappings.emplace_back(mapping->Old, mapping->New);
-    }
-  }
 
   if (Opts.ProgramAction != frontend::GenerateModule && Opts.IsSystemModule)
     Diags.Report(diag::err_drv_argument_only_allowed_with) << "-fsystem-module"