Don't bother running dx when we're testing on the RI.

Also drop the -ea argument to the RI; we don't support assert, so it's
misleading if tests behave differently on the RI.

Change-Id: I4db66ee13fe6b778385778a783ded460b5fcf5f7
diff --git a/test/run-test b/test/run-test
index 7e99c04..8f0d85b 100755
--- a/test/run-test
+++ b/test/run-test
@@ -40,6 +40,7 @@
 export RUN="${progdir}/etc/push-and-run-test-jar"
 export IMAGE=${ANDROID_PRODUCT_OUT}/data/art-test/core.art
 export DEX_LOCATION=/data/run-test/${test_dir}
+export NEED_DEX="true"
 
 info="info.txt"
 build="build"
@@ -64,6 +65,7 @@
         shift
     elif [ "x$1" = "x--jvm" ]; then
         RUN="${progdir}/etc/reference-run-test-classes"
+        NEED_DEX="false"
         shift
     elif [ "x$1" = "x-O" ]; then
         run_args="${run_args} -O"