[objcmt] Introduce "objcmt-white-list-dir-path=" option.

This options accepts a path to a directory, collects the filenames of the files
it contains, and the migrator will only modify files with the same filename.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194710 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index c8ecdc9..9027f70 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2726,6 +2726,7 @@
     Args.AddLastArg(CmdArgs, options::OPT_objcmt_atomic_property);
     Args.AddLastArg(CmdArgs, options::OPT_objcmt_returns_innerpointer_property);
     Args.AddLastArg(CmdArgs, options::OPT_objcmt_ns_nonatomic_iosonly);
+    Args.AddLastArg(CmdArgs, options::OPT_objcmt_white_list_dir_path);
   }
 
   // Add preprocessing options like -I, -D, etc. if we are using the