[arcmt] Add some additional driver flags to optionally emit or save the pre-migration ARC errors.

-arcmt-migrate-emit-errors : Emits the pre-migration ARC errors but it doesn't affect anything else
-arcmt-migrate-report-output : Writes out the pre-migration ARC errors to the provided plist file

rdar://9791454

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135491 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index eb17609..b47a6bd 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1444,6 +1444,9 @@
         CmdArgs.push_back("-arcmt-migrate");
         CmdArgs.push_back("-arcmt-migrate-directory");
         CmdArgs.push_back(A->getValue(Args));
+
+        Args.AddLastArg(CmdArgs, options::OPT_arcmt_migrate_report_output);
+        Args.AddLastArg(CmdArgs, options::OPT_arcmt_migrate_emit_arc_errors);
         break;
       }
     }