Marking more jdk8 tests.

Fixes #881.

--
MOS_MIGRATED_REVID=114731500
diff --git a/src/java_tools/buildjar/javatests/com/google/devtools/build/java/turbine/javac/BUILD b/src/java_tools/buildjar/javatests/com/google/devtools/build/java/turbine/javac/BUILD
index 8914405..83e45e9 100644
--- a/src/java_tools/buildjar/javatests/com/google/devtools/build/java/turbine/javac/BUILD
+++ b/src/java_tools/buildjar/javatests/com/google/devtools/build/java/turbine/javac/BUILD
@@ -1,6 +1,7 @@
 java_test(
     name = "JavacTurbineTest",
     srcs = ["JavacTurbineTest.java"],
+    tags = ["jdk8"],
     deps = [
         "//src/java_tools/buildjar/java/com/google/devtools/build/java/turbine:turbine_options",
         "//src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac:javac_turbine",
@@ -17,6 +18,7 @@
 java_test(
     name = "TreePrunerTest",
     srcs = ["TreePrunerTest.java"],
+    tags = ["jdk8"],
     deps = [
         "//src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac:tree_pruner",
         "//third_party:guava",