Support source versions newer than 8 in Bazel's annotation processors

This quiets some build warnings.

PiperOrigin-RevId: 190958692
GitOrigin-RevId: eef80048e2c59e3be974144ce9cd90b9f90294fb
Change-Id: Ibf4e681bfc1ef540c2012df32d2970ed71240e65
diff --git a/java/com/google/devtools/common/options/processor/OptionProcessor.java b/java/com/google/devtools/common/options/processor/OptionProcessor.java
index 76b9640..5190053 100644
--- a/java/com/google/devtools/common/options/processor/OptionProcessor.java
+++ b/java/com/google/devtools/common/options/processor/OptionProcessor.java
@@ -36,7 +36,6 @@
 import javax.annotation.processing.ProcessingEnvironment;
 import javax.annotation.processing.RoundEnvironment;
 import javax.annotation.processing.SupportedAnnotationTypes;
-import javax.annotation.processing.SupportedSourceVersion;
 import javax.lang.model.SourceVersion;
 import javax.lang.model.element.AnnotationMirror;
 import javax.lang.model.element.Element;
@@ -74,7 +73,6 @@
  * <p>These properties can be relied upon at runtime without additional checks.
  */
 @SupportedAnnotationTypes({"com.google.devtools.common.options.Option"})
-@SupportedSourceVersion(SourceVersion.RELEASE_8)
 public final class OptionProcessor extends AbstractProcessor {
 
   private Types typeUtils;
@@ -84,6 +82,11 @@
   private ImmutableMap<Class<?>, PrimitiveType> primitiveTypeMap;
 
   @Override
+  public SourceVersion getSupportedSourceVersion() {
+    return SourceVersion.latestSupported();
+  }
+
+  @Override
   public synchronized void init(ProcessingEnvironment processingEnv) {
     super.init(processingEnv);
     typeUtils = processingEnv.getTypeUtils();