ART: Compile run-tests with Java 7.

This fixes run-tests with EXPERIMENTAL_USE_JAVA8=true.

Change-Id: I269664fc65a1d6c244c3f6191e332eb2751b5c0e
diff --git a/test/run-test b/test/run-test
index 6e13b8a..60e008c 100755
--- a/test/run-test
+++ b/test/run-test
@@ -41,7 +41,7 @@
 fi
 checker="${progdir}/../tools/checker/checker.py"
 export JAVA="java"
-export JAVAC="javac -g"
+export JAVAC="javac -g -source 1.7 -target 1.7 -Xlint:-options"
 export RUN="${progdir}/etc/run-test-jar"
 export DEX_LOCATION=/data/run-test/${test_dir}
 export NEED_DEX="true"