Include -D files in crash report repro scripts. (PR13255)

Now that we're only using -frewrite-includes rather than full preprocessing
when producing repro source files, we should also include command line macro
definitions in the repro script.

I don't have a test case for this because I'm not sure if/how I can open the
crash report file when the name is only known by scraping the crash report
output. Suggestions welcome if anyone thinks it'd be helpful.

git-svn-id: 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index 2f2d07c..9b5783d 100644
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -503,7 +503,6 @@
         // Strip away options not necessary to reproduce the crash.
         // FIXME: This doesn't work with quotes (e.g., -D "foo bar").
         SmallVector<std::string, 16> Flag;
-        Flag.push_back("-D ");
         Flag.push_back("-I ");
         Flag.push_back("-o ");