Implement support for GCC's -dD mode, which dumps -E output *and*
macro definitions.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68884 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 4d1aca4..7c73780 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -474,6 +474,7 @@
     CmdArgs.push_back("-fno-common");
 
   Args.AddLastArg(CmdArgs, options::OPT_dM);
+  Args.AddLastArg(CmdArgs, options::OPT_dD);
 
   Args.AddAllArgValues(CmdArgs, options::OPT_Xclang);