Dex2oat support for multiple oat file and image file outputs.

Multiple changes to dex2oat and the runtime to support a --multi-image
option. This generates a separate oat file and image file output for
each dex file input.

Change-Id: Ie1d6f0b8afa8aed5790065b8c2eb177990c60129
diff --git a/compiler/oat_test.cc b/compiler/oat_test.cc
index cd0f0d2..58f46d6 100644
--- a/compiler/oat_test.cc
+++ b/compiler/oat_test.cc
@@ -121,7 +121,8 @@
                                               false,
                                               timer_.get(),
                                               -1,
-                                              ""));
+                                              "",
+                                              nullptr));
   }
 
   bool WriteElf(File* file,