Add options for base dir and redirecting files to IRT open resource and use it.

pnacl/driver/driver_env.py

Index: pnacl/driver/driver_env.py
diff --git a/pnacl/driver/driver_env.py b/pnacl/driver/driver_env.py
index 4fca9a35d44d79198f45b28c1bdf0d20152a7e84..7fd2e8a5e627238b5b432e3dc1d577f30327992e 100755
--- a/pnacl/driver/driver_env.py
+++ b/pnacl/driver/driver_env.py
@@ -130,10 +130,7 @@ INITIAL_ENV = {
   'SEL_UNIVERSAL_PREFIX': '${USE_EMULATOR ? ${EMULATOR}}',
   'SEL_UNIVERSAL'       : '${SCONS_STAGING}/sel_universal${EXEC_EXT}',
   # NOTE: -Q skips sel_ldr qualification tests, -c -c skips validation
-  # NOTE: We are not using -B to load the IRT, since the translators do not
-  # use the IRT.
   'SEL_UNIVERSAL_FLAGS' : '--abort_on_error ' +
-                          '--uses_reverse_service ' +
                           '${USE_EMULATOR ? -Q -c -c --command_prefix ${EMULATOR}}',
 
   'IRT_STAGING'         : '${IRT_STAGING_%ARCH%}',